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Journal Cover Journal of Applied Polymer Science
  [SJR: 0.578]   [H-I: 127]   [144 followers]  Follow
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0021-8995 - ISSN (Online) 1097-4628
   Published by John Wiley and Sons Homepage  [1597 journals]
  • Improved mechanical and antibacterial properties of thermoplastic
           polyurethanes by efficient double functionalization of silver
    • Authors: Daniel Ramirez; Franklin Jaramillo
      Abstract: When making nanocomposites, there is a big challenge to obtain both functional and mechanical enhancement. In this study, a new in situ polymerization methodology for the incorporation of surface modified silver nanoparticles (AgNPs) in a thermoplastic polyurethane matrix was developed. AgNPs with contents ranging from 0 to 1.5 wt % were used. A double functionalization of the nanoparticles with oleic acid was performed, which lead to a reaction of carboxylic acid groups in the nanoparticle's surface with isocyanate groups of the 4,4′-methylene diphenyl diisocyanate monomer as corroborated from the Raman results. The successful incorporation of the nanoparticles was verified with EDS, TGA, and Raman measurements. Thermal properties of nanocomposites were investigated by DSC. AgNPs made positive impact in two ways: first, increased more than twice the elastic modulus, as studied via nanoindentation measurements and second, based on the inhibition zone method, great bactericidal effectiveness for nanocomposites containing 1.5 wt % AgNPs was observed for Escherichia coli. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46180.
      PubDate: 2018-01-13T02:01:01.083954-05:
      DOI: 10.1002/app.46180
  • Surface grafting of styrene on polypropylene by argon plasma and its
           adsorption and regeneration of BTX
    • Authors: Zhengwei Luo; Haonan Chen, Jianjian Xu, Mulin Guo, Zhouyang Lian, Wuji Wei, Binghua Zhang
      Abstract: Active macromolecular free radicals were generated on polypropylene (PP) fiber surfaces by argon plasma irradiation, and surface-modified PP fibers (PP-g-St fibers) were prepared by in situ grafting reaction of styrene monomers (St). The prepared samples were characterized by Fourier transform infrared, NMR, X-ray photoelectron spectroscopy, scanning electron microscopy, and thermogravimetric analysis. Effects of reaction parameters on grafting percentage were studied, and adsorption capacities of PP-g-St fibers for benzene, toluene, and xylene (BTX) were evaluated. Regeneration adsorption efficiencies after adsorption of pure BTX and BTX emulsion and solution in water were explored. The results indicated that, using pure St as the monomer, the optimum input power, irradiation time, and grafting reaction time are 90 W, 3 min, and 3 h, respectively, and the grafting percentage of St reached 5.7% when pure St was used. The characterization results demonstrated that St was grafted onto the surface of the PP fibers. Compared to pristine PP fibers, the adsorption capacities of PP-g-St fibers toward toluene and xylene emulsions and solutions in water increased. In addition, regeneration adsorption efficiencies of modified fibers remained>90% after six cycles of regeneration adsorption experiments, which showed excellent regeneration ability. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 136, 46171.
      PubDate: 2018-01-13T02:00:53.052263-05:
      DOI: 10.1002/app.46171
  • Structural and physicochemical studies of hydration of crosslinked TBA
           polyacrylates with different substitution degrees of H+ ions with TBA+
    • Authors: Irina S. Terekhova; Andrey Yu. Manakov, Galina V. Villevald
      Abstract: X-ray powder diffraction studies and physicochemical studies have been carried out of the hydrate phases formed in binary water systems with crosslinked tetrabutylammonium (TBA) polyacrylates (n = 1%) in mixed [x(C4H9)4N + (100−x)H] form with low degrees of substitution of proton ions of the carboxylic groups in poly(acrylic acid) for TBA cations x = 40%, 30%, and 20%. As was shown by structural studies, the clathrate hydrate is formed in the water system with the polyacrylate in the mixed form with x = 40%. The structure is analogous to that of earlier studied hydrates formed by crosslinked polyacrylates in mixed [x(C4H9)4N + (100−x)H] form with higher values of x = ∼100%, 80%, and 60% and can be related to the tetragonal structure I, characteristic of the ionic clathrate hydrates of TBA salts with monomeric anions. Decomposition temperature and fusion enthalpy of the studied hydrate were determined using differential thermal analysis and calorimetric methods. It was revealed that the further decrease of x led to the destruction of clathrate hydrate framework. According to the results of X-ray powder diffraction research, the phase of ice is crystallized instead of the hydrate phase in water systems with the polyacrylates with x = 30% and 20%. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46209.Powder diffraction patterns (248 K) of the hydrates of crosslinked TBA polyacrylates [x(C4H9)4N + (100−x)H]COORn with degree of crosslinking n = 1% in dependence of the degree of substitution (x) of proton ions of the carboxylic groups for TBA cations. Sticks correspond to the positions expected for ice Ih reflections.
      PubDate: 2018-01-13T02:00:24.02383-05:0
      DOI: 10.1002/app.46209
  • Dielectric properties of thin films of Babassu-based polymer and
           polyaniline blends
    • Authors: Giovanni P. da Cunha; Fernando de Matos Borges, Guilherme Dognani, Giovani B. Bacarin, Flávio C. Cabrera, Aldo E. Job, José Milton E. Matos, Maria Letícia Vega, Helder N. da Cunha
      Abstract: In the present work, we describe the preparation and subsequent characterization of polymeric blends consisting of a monoglyceride (MG) synthesized from the Babassu's oil and the already commonly employed polyaniline (PAni). By following changes in the complex impedance of capacitor-like devices we observe that the presence of MG in the PAni/MG blends decreases electrical conductivity and that this decrease is a function of the content of MG in the blend, i.e., the blend with 30% of MG shows Z′ about seven times greater than the one with 10% of MG. Fourier transform infrared measurements prove the formation of MG and the presence of secondary amine groups (NH bonds) in the blends, which allow for the chemical doping of PAni by protonation, further studies are necessary to access the viability of employing this new material as active layer in electronic organic devices. Atomic force microscopy images show the formation of agglomerates due to the presence of MG. In addition, the polymeric mixture acts only as a blend, providing a physical interaction between different components. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46198.
      PubDate: 2018-01-12T09:00:39.510223-05:
      DOI: 10.1002/app.46198
  • Sustained release of dexamethasone from drug-loading PLGA scaffolds with
           specific pore structure fabricated by supercritical CO2 foaming
    • Authors: Xin Xin; Yi-Xin Guan, Shan-Jing Yao
      Abstract: Inducing differentiation of bone marrow stem cells to generate new bone tissue is highly desirable by controlling the release of some osteoinductive or osteoconductive factors from porous scaffolds. In this study, dexamethasone was selected as a representative of small molecule drugs and dexamethasone-loading porous poly(lactide-co-glycolide) (PLGA) scaffolds were successfully fabricated by supercritical CO2 foaming. Scanning electron microscopy images showed that scaffolds had rough and relatively interconnected pores facilitating cells adhesion and growth. Specially, dexamethasone which was incorporated into PLGA matrix in a molecularly dispersed state could serve as a nucleation agent to be helpful for the formation of interconnected pores. Dexamethasone-loading porous PLGA scaffolds exhibited sustained release profile, and the delivery of dexamethasone from porous scaffolds could last for up to 2 months. The cumulative released amount of dexamethasone was relevant with drug loading capacity (1.66%–2.95%) and pore structure of scaffolds; while the release behavior was anomalous (non-Fickian) transport by fitting with the simple exponential equation, which had a diffusional exponent n higher than 0.5. It is feasible to fabricate drug-loading porous scaffolds by supercritical CO2 foaming with specific pore structure and sustained release profile, which can be well applied in bone tissue engineering. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46207.
      PubDate: 2018-01-12T09:00:34.282067-05:
      DOI: 10.1002/app.46207
  • Evaluation of thermomechanical properties of polyvinyl butyral
           nanocomposites reinforced with graphene nanoplatelets synthesized by in
           situ polymerization
    • Authors: Jean Carlos Hoepfner; Marcio Rodrigo Loos, Sérgio Henrique Pezzin
      Abstract: In this work, polyvinyl butyral (PVB) nanocomposites reinforced with 0.5 to 2.5 wt % of graphene oxide (GO) and graphene nanoplatelets (GNP) were synthesized via in situ polymerization. Dynamic mechanical analysis showed that PVB/GO 2.5 wt % nanocomposites present the largest storage modulus, with increases of 10 °C in the PVB glass transition temperature. The degree of entanglement and the reinforcement efficiency factor (C coefficient) were evaluated using the dynamic mechanical analysis results and correlated with scanning electron microscopy analyses. The degree of entanglement and C coefficient values were higher for PVB/GO 2.5 wt %, enabling the enhancement of PVB mechanical properties. The adhesion factor A was used to evaluate the interfacial interaction, evidencing an improvement in the nanoparticle/matrix adhesion for PVB/GO 2.5 wt % caused by interactions between GO oxygenated groups. For the samples reinforced with GNP, the results of storage modulus, degree of entanglement, coefficient C, and adhesion factor A were not significantly modified, due to weak interfacial interactions with PVB, preventing the exfoliation of GNP in PVB during the in situ polymerization process. Therefore, in situ polymerization will improve the dispersion and final properties of the nanocomposite with PVB only if the nanoparticle has a relevant interfacial interaction during the synthesis process. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46157.
      PubDate: 2018-01-12T09:00:30.454713-05:
      DOI: 10.1002/app.46157
  • Preparation of bi-continuous poly(acrylonitrile-co-methyl acrylate)
           microporous membranes by a thermally induced phase separation method
    • Authors: Linli Tan; Na Han, Longfei Zhang, Yongqiang Qian, Xingxiang Zhang, Zhenyu Cui, Jun Cai
      Abstract: Poly(acrylonitrile-co-methyl acrylate) (P(AN-MA)) flat microfiltration membranes were successfully prepared via the thermally induced phase separation (TIPS) method, by using low polar caprolactam (CPL) and methoxypolyethylene glycol 550 (MPEG 550) as the mixed diluent. In this work, P(AN-MA) membranes exhibit bi-continuous networks, porous surfaces, high porosity, and big pore size, when membrane fabricated from a high MPEG 550 content, low P(AN-MA) concentration, and small cooling rate, it can be dry state preservation and do not need to be impregnated by any solvent. When the ternary system was composed of 15 wt % P(AN-MA), 12.5 wt % CPL, and 87.5 wt % MPEG 550, formed at 25 °C air bath, membrane has the highest water flux of 4420 L m−2 h−1. The obtained P(AN-AN) membrane displays a high carbonic black ink rejection ranging from 83.7 to 98.5 wt %. Moreover, P(AN-MA) polymer not only retains the advantages of PAN but also reduces the polar component from 16.2 to 10.77 MPa0.5. It can be used membrane matrix to obtain pore structure and excellent mechanical property membrane via TIPS. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46173.
      PubDate: 2018-01-11T01:26:13.576518-05:
      DOI: 10.1002/app.46173
  • Rigid polyisocyanurate–waterglass foam composite: Preparation,
           mechanism, and thermal and flame-retardant properties
    • Authors: Guo-Dong Feng; Li-Hong Hu, Yan Ma, Meng Zhang, Cheng-Guo Liu, Yong-Hong Zhou
      Abstract: A rigid polyisocyanurate–waterglass foam (PIWGRF) composite was prepared with polyaryl poly(methylene isocyanate) and waterglass (WG) as the main materials; water as a blowing agent, and no polyols. We speculated the formation mechanism of the PIWGRFs on the basis of the analysis of experiment data, scanning electron microscopy characterization, and transmission electron microscopy. The results show that three-dimensional nanoflakes derived from the cured WG was observed; this was connected with polyisocyanurate by secondary bonding (SiOHN). Thermogravimetric testing indicated that the thermal stability and residual mass (34%) of the PIWGRFs were significantly higher than those of rigid traditional polyurethane foams (T-PUFs). When the core density of the PIWGRFs was 32.6 kg/m3, the strength was up to 162.9 KPa by excessive filling. The flame retardancy of the PIWGRFs, including the time to ignition, heat-release rate, total smoke of release, and limiting oxygen index, was obviously better than that of the T-PUFs. The structure of the residual char was more dense and orderly; this was also an effective barrier layer. The reason was attributed to the fact that the WG did not contain combustible elements. So, the PIWGRFs had excellent thermal stability, flame retardancy, and environmental friendliness. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 136, 46182.
      PubDate: 2018-01-11T01:22:02.039124-05:
      DOI: 10.1002/app.46182
  • Templating polyacrylamide hydrogel for interconnected microstructure and
           improved performance
    • Authors: Maria Bassil; Georges El Haj Moussa, Mario El Tahchi
      Abstract: In this study, the pressure and temperature are monitored during acrylamide polymerization and their effects on the mechanical properties and swelling of the resulting hydrogel are investigated. The polymerization kinetic and network formation mechanism are correlated to the environmental thermodynamic conditions under which the hydrogels are polymerized. Then, the swelling and Young's modulus are measured and shown to be tunable along a wide range of values. The swelling ratio varies between 50 and 2262 while Young's modulus varies between 10.99 and 40.70 kPa. In addition, the formation of macroporous hydrogel with channel like structures along the vacuum direction under a reduced pressure of 5 mbar is reported. The macroporous hydrogel has a modulus of 40.70 kPa and shrink approximatively three times faster than the hydrogel polymerized under normal pressure and has a modulus of 10.99 kPa. Hence, this interconnected network can overcome the fluid diffusion limitations of bulk hydrogels without compromising the mechanical properties. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 136, 46205.
      PubDate: 2018-01-11T01:21:34.260411-05:
      DOI: 10.1002/app.46205
  • The colloidal properties of alkaline-soluble waterborne polymers
    • Authors: Jurgen Scheerder; Remy Dollekens, Harm Langermans
      Abstract: Waterborne polymer dispersions are widely used in coatings and graphic arts markets as environmentally friendly and more sustainable alternatives to solvent borne binders. Traditionally, waterborne (meth)acrylic dispersions are prepared by emulsion polymerization using low molar mass surfactants as a key ingredient to control particle size. However, these surfactants can have a negative influence on the performance of coatings such as reduced water resistance and adhesion. To mitigate the negative effects of surfactants, polymer latexes have been developed that employ alkaline-soluble polymers as the sole stabilizer for a subsequent emulsion polymerization step. In this way surfactant-free polymer dispersions are obtained. Despite the high commercial impact and relevance of this technology, fundamental studies regarding the physicochemical properties of the alkaline-soluble polymers are lacking. In this article, the synthesis and colloidal properties of alkaline-soluble waterborne methacrylic copolymers are reported. The dissolution behavior and colloidal properties of these alkaline-soluble polymers were studied as function of molar mass, acid content, and pH. The dissolving polymer particles were characterized using static and dynamic light scattering, static and dynamic surface tension measurements, and cryogenic-transmission electron microscopy analysis. It is concluded that the dissolution mechanism of alkaline-soluble polymers follows a gradual process. As the pH increases deprotonation of the carboxylic acid groups swells the particle enhancing the further swelling with water. At a certain amount of base, the particles disintegrate into small polymer aggregates while the most water-soluble polymer chains are dissolved in the water phase. An important learning is that part of the alkaline-soluble polymer resides in very small particles (
      PubDate: 2018-01-11T01:21:01.750739-05:
      DOI: 10.1002/app.46168
  • Enhanced adhesion force based on microphase separation induced by
           complexation of ferric ions and polyurethane matrix
    • Authors: Xie Li; Wei Li, Xiaolin Wang, Heling Guo, Rongjie Wang, Xuhong Guo, Cuihua Li, Xin Jia
      Abstract: Waterborne polyurethane elastomer (WPU) has been widely used as a glue, but it still has some drawbacks, including a long cure time and weak adhesive force. In order to overcome these drawbacks, a new composite [PU/ferric ion complexation (Fe/PU)] with high adhesive strength was successfully prepared using ferric ion (Fe3+) as a complexing agent. Fourier transform infrared spectroscopy, differential scanning calorimetry, dynamic mechanical analysis, and tensile testing were used to characterize the chemical structure and mechanical properties of the as-obtained composites. Introduction of the ferric ion induces a certain degree of microphase separation, resulting in better mechanical strength and interfacial adhesion. The mechanical properties of the PU composite with ferric ions are higher than that of pure PU. The adhesive strength of the 25%-Fe/PU composite is 32.46 ± 3.1 MPa, exhibiting superior adhesive strength. The tensile strength was enhanced 34%, and the elongation was enhanced 23.6% compared to pure PU. Furthermore, the Fe/PU composite, coordinated with ferric ions, exhibits an enhanced storage modulus and reduced loss coefficient compared to PU. We can foresee that Fe/PU composites will play an important role in the building and engineering areas. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46069.
      PubDate: 2018-01-11T01:20:55.352278-05:
      DOI: 10.1002/app.46069
  • Mechanical and thermal properties of coal gasification fine slag
           reinforced low density polyethylene composites
    • Authors: Weidong Ai; Bing Xue, Cundi Wei, Kuizhou Dou, Shiding Miao
      Abstract: Coal gasification fine slag (CGFS) was processed via a grading technique. The CGFS products (CGFS-S1, CGFS-S2, CGFS-S3) with different sizes were obtained. Effects of particle size and unburned carbon on tensile properties of filled low density polyethylene (LDPE) were studied within the CGFS weight fractions ranging from 10 to 50 wt %. The tensile strength was found to increase with decreasing CGFS size, and the tensile properties exhibited good performance, owing to unburned carbon. The tensile strength of the composites increased with increasing CGFS-S3 weight fraction. The analysis of mathematical model and SEM revealed that the firm improvement of tensile strength resulted from the strong interactions between LDPE polymer chains and CGFS-S3 particles, and good dispersion of CGFS-S3 in resin. Thermogravimetric analysis proved obvious reinforcement in thermal-oxidative stability by incorporation of CGFS-S3. The degree of crystallinity of LDPE/CGFS-S3 showed the first increased and then decreased variation tendency. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46203.
      PubDate: 2018-01-10T04:54:33.385607-05:
      DOI: 10.1002/app.46203
  • Nitrogen-doped graphene as an alternative to ecotoxic zinc oxide in
    • Authors: Yulia Glebova; Nikolai Severin, Vladimir Shershnev, Jürgen P. Rabe
      Abstract: Zinc oxide (ZnO) is an essential ingredient in industrial rubber production; it regulates the onset of vulcanization, accelerates the kinetics of vulcanization, and improves the mechanical properties of rubber. However, environmental pollution with ZnO is a concern because it is recognized to be significantly ecotoxic and might also have adverse effects on human health. One of the major sources of ZnO environmental pollution is rubber items, tires in particular. Nitrogen (N)-doped graphene is a promising next-generation catalyst. We show here that the replacement of 3 phr ZnO by just 0.1 phr N-doped graphene in styrene–butadiene rubber reduced the vulcanization onset time by more than a factor of two while retaining the fast vulcanization kinetics and enhancing the tensile strength in comparison with rubber with just ZnO. A shorter vulcanization time implies energy savings, which, together with the nontoxicity of N-graphene, should make the resulting rubbers substantially more environmentally friendly. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46116.
      PubDate: 2018-01-10T04:54:18.767253-05:
      DOI: 10.1002/app.46116
  • Influence of Syzygium cumini leaves extract on morphological, thermal,
           mechanical, and antimicrobial properties of PVA and PVA/chitosan blend
    • Authors: Deepak Kasai; Ravindra Chougale, Saraswati Masti, Raju Chalannavar, Ravindra Malabadi, Ramesh Gani
      Abstract: In the present work, poly(vinyl alcohol)/Syzygium cumini leaves extract (PSN) and poly(vinyl alcohol)/chitosan/S. cumini leaves extract blend films were prepared by solution casting technique. The films were characterized by using scanning electron microscopy, atomic force microscopy, X-ray diffraction study, Fourier transform infrared spectroscopy, thermogravimetric analysis, and universal testing machine. The results indicated that the appreciable physical interaction at lower concentrations of S. cumini leaves extract in the PVA and PVA/chitosan films contribute to the smooth uniform morphology, increased the degree of crystallinity, degradation temperature, and improved mechanical properties. Further, films were analyzed with water contact angle analyzer which illustrates that blend films were hydrophilic (PSN-1) and hydrophobic (PCS-1) in nature. However, blend films were also subjected to the antimicrobial study, which revealed that inclusion of S. cumini leaves extracts significantly enhanced the antibacterial activity in the PVA and PVA/chitosan film. With all of these results, fabricated blends can find potential applications in packaging material to extend the shelf life of foodstuffs. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46188.
      PubDate: 2018-01-08T08:22:36.574549-05:
      DOI: 10.1002/app.46188
  • Quantitative relationships between intermolecular interaction and damping
           parameters of irganox-1035/NBR hybrids: A combination of experiments,
           molecular dynamics simulations, and linear regression analyses
    • Authors: Jing Zhu; Xiuying Zhao, Li Liu, Meng Song, Sizhu Wu
      Abstract: The damping mechanism of phenol(3,5-bis(1,1-dimethylethyl)-4-hydroxybenzenepropanoic acid thiodi-2,1-ethanediyl ester, abbreviated as Irganox-1035)/nitrile-butadiene rubber hybrids was studied by combining experiments, computer simulations, and linear regression analyses. Four important damping parameters [loss peak (tan δmax), effective loss area (TA), glass transition temperature (Tg), and effective temperature region (ΔT)], were obtained by dynamic mechanical thermal analyses. Three intermolecular interaction parameters [the number of intermolecular hydrogen bonds (NHBs), binding energy (Ebinding), and fractional free volume (FFV)], were calculated by molecular dynamics simulations. Using linear regression analyses, the quantitative relationships between the intermolecular interaction and damping parameters were investigated. Linear and significant relationships between intermolecular interactions (NHBs and Ebinding) and damping parameters (tan δmax and TA) (R2 > 0.9; P 
      PubDate: 2018-01-08T08:21:54.850374-05:
      DOI: 10.1002/app.46202
  • Investigation of the mechanical, thermal, and anticorrosion properties of
           epoxy nanocomposite coatings: Effect of synthetic hardener and nanoporous
    • Authors: Mehdi Naderi; Morteza Hoseinabadi, Mohammad Najafi, Siamak Motahari, Mohammad Shokri
      Abstract: In the present study, epoxy samples containing nanoporous graphene (NPG) were synthesized and analyzed in terms of mechanical, morphological, thermal, adhesion, and anticorrosion properties. To this end, the employed curing agents (hardeners) were synthesized and NPG content was varied from 0 to 1 wt %. By using a hardener with aliphatic side chains, the toughness of the nanocomposite was improved without a decrease in the modulus. Adding 1 wt % NPG increased the modulus of the nanocomposite by about 30%. The dynamic mechanical results showed an increment in the glass transition of the samples containing 1 wt % NPG. Field emission scanning electron microscopy images were used to observe the fracture surface of the nanocomposites. The thermogravimetric analysis analysis also confirmed that using synthetic hardener and NPG as the nanofiller enhanced the thermal resistance of the samples. The images of the protected metal panel surfaces and their coatings were used to study adhesion and anticorrosion properties. These results indicated that the hardener synthesized in this work along with NPG improved the mechanical, thermal, adhesion, and anticorrosion properties of the epoxy nanocomposites effectively. The specific characteristic of the synthetic hardener was its chemical structure including both aliphatic and cyclic polyamines as the side groups. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 136, 46201.
      PubDate: 2018-01-08T08:21:45.112566-05:
      DOI: 10.1002/app.46201
  • Simple method for preparation of thermally expandable microspheres of PMMA
           encapsulating NaHCO3 via thermally induced phase separation
    • Authors: Shuqian Zhou; Zheng Li, Zhengfa Zhou, Weibing Xu, Haihong Ma, Fengmei Ren
      Abstract: Thermally expandable microspheres (TEMs) employing poly(methyl methacrylate) (PMMA) as shell and sodium bicarbonate (NaHCO3) as core were prepared by a simple method of thermally induced phase separation (TIPS). The addition of NaHCO3 improved the foaming properties of TEMs. The effects of preparation parameters on the morphology, amount of encapsulated NaHCO3, and foaming properties of TEMs were studied; the parameters investigated included the quench rate, the molecular weight (Mw) and amount of PMMA, and the amount of NaHCO3. The results show that when 0.5 g of PMMA 50k, 3 g of NaHCO3, and 50 g of ethanol were used, with quenching temperature at 0 °C, the TEMs were fully spherical and the maximum expansion volume of TEMs was about 3.8 times the original volume. The expansion volume of TEMs increased with increasing amount of encapsulated NaHCO3, and the foaming onset temperature and temperature of complete bursting of TEMs were related to the Mw of PMMA. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46179.
      PubDate: 2018-01-08T08:21:36.717171-05:
      DOI: 10.1002/app.46179
  • Study on the performance of flame-retardant esterified starch-modified
           cassava dregs-PBS composites
    • Authors: Xiaopeng Yue; Jian Li, Pengjie Liu, Yicun Lin, Xin Du
      Abstract: Esterified starch was used as an interfacial modifier to treat the surface of cassava dregs. The treated fiber was used to prepare flame-retardant poly(butylene succinate) (PBS)/cassava dregs fiber composites with the incorporation of intumescent flame retardants (IFR). The mechanical performance and flame-retardant properties of composites were investigated. Experimental data showed that an appropriate cassava fiber loading favored the mechanical performance of composites. When the total filler content was 30 wt % [m(cassava dregs):m(IFR) = 1:5], in comparison with those of composite prepared by 30 wt % IFR, the tensile and impact strengths of composite increased by 40 ± 7 and 62 ± 8%, respectively. Besides, the limited oxygen index value of 37.3% and UL-94 V0 rate of composite could be achieved. Possible flame retardant mechanism was proposed. The combusted residue of incorporated cassava dregs could play a support effect in the three-dimensional charred layer formed by the combustion products of IFR and PBS. The three-dimensional intumescent charred layer, and the formation of incombustible gas, such as NH3, play an important role in insulation, oxygen barrier, thereby effectively improving the flame retardancy and thermal stability of composites. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46210.
      PubDate: 2018-01-08T08:21:29.222274-05:
      DOI: 10.1002/app.46210
  • Self-healing hydrogel of poly(vinyl alcohol)/graphite oxide with
           pH-sensitive and enhanced thermal properties
    • Authors: Sui Wang; Zheng Zhang, Bing Chen, Jia Shao, Zhiyong Guo
      Abstract: Supramolecular hydrogel is a fascinating polymeric material composed of three-dimensional noncovalent networks with many outstanding properties, especially reversible relevant performances. A self-healing supramolecular hydrogel of poly(vinyl alcohol)/graphite oxide, with reversible pH responsiveness and good thermal stability, was prepared. The morphology, functional group changes, swelling performance, thermal stability, rheological performance, and self-healing property of the PVA/GO hydrogel were investigated. A probable mechanism between the components and potential applications were also examined in our study. The experimental results show that the PVA/GO hydrogel was not only self-healable without external stimulus or addition of any healing agents, but also pH sensitive and with good thermal stability. Green ingredients (PVA and GO) and a simple synthesis method (a freezing/thawing treatment) may pose little threat to the environment and also promote the production of such hydrogels. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46143.
      PubDate: 2018-01-08T08:21:17.652266-05:
      DOI: 10.1002/app.46143
  • Studies on crosslinking and thermal behavior of phthalonitrile end-capped
           imide monomer in presence of aromatic amines
    • Authors: Devendra Kumar; Veena Choudhary
      Abstract: This paper describes the synthesis and characterization of a bisphthalonitrile monomer having an imide linkage prepared by reacting 4,4′-(hexafluoroisopropylidene) diphthalic anhydride with 4-(4-aminophenoxy) phthalonitrile. The structure of the monomer was confirmed by Fourier transform infrared, 1H-NMR, and 13C-NMR spectroscopy. The curing behavior of bisphthalonitrile monomer was investigated in the absence or presence of different diamines using differential scanning calorimetry. Diamines 4,4′-diaminodiphenyl ether (DDE) and 4,4′-diaminodiphenylsulfone (DDS) were used to investigate the effect of the structure of diamines on the curing behavior of bisphthalonitrile monomer. An exothermic transition due to curing was observed in the DSC scan, and the curing temperature was found to be dependent on the nucleophilicity of the amine. DDE was found to be more reactive than DDS. The thermal stability of the cured resins was evaluated using thermogravimetry in nitrogen atmosphere. All of the cured samples were stable up to 400 °C and leave behind 62% char residue at 800 °C, which was found to be dependent on the structure of the diamine used for curing as well as on the curing conditions. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46151.
      PubDate: 2018-01-08T08:21:08.505598-05:
      DOI: 10.1002/app.46151
  • Heat- and light-induced thiol-ene oligomerization of soybean oil-based
    • Authors: Grigor B. Bantchev; Karl E. Vermillion, James C. Lansing, Girma Biresaw
      Abstract: Polymercaptanized soybean oil (PMSO), the product of a thiol-ene reaction between soybean oil and hydrogen sulfide, is a material of interest as a lubricant additive and polymer precursor. We investigated with gel permeation chromatography, nuclear magnetic resonance (one-dimensional and two-dimensional), gas chromatography–mass spectrometry, and viscometry the changes that occur with PMSO upon heating or ultraviolet irradiation. The observed changes were due to a further thiol-ene reaction between the thiol groups and the residual unsaturation. The formation of oligomers was a result of new sulfide bridges. Additionally, tetrahydrothiophene moieties were detected. An almost linear increase of the average molecular weight (MW) and the polydispersity index (PDI) was observed upon heat treatment [number-average MW (Mn) = 1180 Da, PDI = 1.32 for PMSO, Mn = 1720 Da, PDI = 2.17 for PMSO that was heated for 1000 h at 130 °C]. PDI correlated best with the z-average MW. The Mn was the best predictor of the viscosity. For samples with close Mn, the higher PDI corresponded to a higher viscosity index. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46150.
      PubDate: 2018-01-08T08:21:01.703211-05:
      DOI: 10.1002/app.46150
  • Properties and pervaporation performance of poly(vinyl alcohol) membranes
           crosslinked with various dianhydrides
    • Authors: Sheng Xu; Liang Shen, Cailian Li, Yan Wang
      Abstract: In this work, three dianhydrides with similar chemical structures, 3,3′,4,4′-benzophenone tetracarboxylic dianhydride (BTDA), 4,4′-oxydiphthalic anhydride (ODPA), and pyromellitic dianhydride (PMDA), are employed for the crosslinking modification of poly(vinyl alcohol) (PVA) membranes for ethanol dehydration via pervaporation. The changes in crosslinking degree, surface hydrophilicity, and glass-transition temperature are investigated and compared. Compared to the pure PVA membrane, all crosslinked membranes show higher fluxes but lower separation factors, because of the higher fractional free volume and the lower hydrophilicity by the crosslinking of the PVA matrix, respectively. In addition, all crosslinked PVA membranes exhibit similar flux, and the separation factor presents a decreasing order of PVA/PMDA-2 > PVA/ODPA-2 > PVA/BTDA-2, which is in the reverse order of their hydrophilicity, probably because of the reduction in the swelling resistance. With the PMDA content increasing from 0.01 to 0.04 mol/(kg PVA) in the PVA/PMDA crosslinked membranes, the crosslinking degree is enhanced and the hydrogen bonding is weakened, resulting in a flux increase from 120.2 to 190.8 g m−2 h−1, but the separation factor declines from 306 to 58. This work is believed to provide useful insight on the chemical modification of PVA membranes for pervaporation and other membrane-based separation applications. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46159.
      PubDate: 2018-01-08T08:20:52.341186-05:
      DOI: 10.1002/app.46159
  • Structure–property relationship in PP/LDPE blend composites: The
           role of nanoclay localization
    • Authors: Tladi Gideon Mofokeng; Suprakas Sinha Ray, Vincent Ojijo
      Abstract: This article reports, for the first time, on how the kinetics and thermodynamics of the melt-processing control the nano/micro-structure development and properties of nanoclay-filled polypropylene (PP)/low-density polyethylene (LDPE) blend ternary composites. Morphological characterization suggests that the nano/micro-structure of the PP/LDPE (80/20) blend can be controlled by incorporating nanoclay alone or by adding a mixture of organoclay and maleated compatibilizers. Simultaneous mixing of PP, LDPE, maleated compatibilizers, and organoclay results in homogeneous distribution of intercalated silicate layers in all the phases of the blend, a feature which profoundly affects the thermal stability and tensile and rheological properties of the blend composites. For example, the elongation-at-break for PP increases from 28.1 to 155.6% for composite containing both organoclay and maleated compatibilizers, whereas the thermal stability for PP increases from 269.8 to 303.3 °C for the same composite. However, the impact strength of the PP/LDPE blend decreases with incorporation of organoclay, regardless of the phase in which the nanoclay particles are localized. In summary, the obtained results show that regardless of the phase in which the nanoclay is localized, the morphology, and hence the properties, of the ternary composites are superior to those of the neat blend. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46193.
      PubDate: 2018-01-08T08:20:48.357637-05:
      DOI: 10.1002/app.46193
  • Aloe vera gel influence on the micellization behavior of copolymer
           Pluronic F127: A potential photosensitizer carrier for topical application
    • Authors: Luis Alberto Soto Dantas Silva; Rafael Leone da Cruz de Jesus, Raildo Alves Fiuza-Junior, Heloysa Martins Carvalho Andrade, Isabel Cristina Rigoli, Rosana Maria Nascimento de Assunção, José Mario Barichello, Renata Galvão de Lima
      Abstract: This work describes the influence of aloe vera gel on Pluronic F127 triblock copolymer (F127) micellization behavior. Aloe vera gel was obtained from aloe vera mucilage found in leaf pulp. F127 (20% w/w) gel and the aloe vera/F127 blend gel were obtained by using the cold method. Fourier transform infrared spectroscopy and X-ray diffraction analyses of lyophilized samples did not show any important copolymer interaction between aloe vera gel and F127. However, in aqueous medium, the dynamic light scattering data showed that there was an important reduction in micelle size with increasing temperature of the aloe vera/F127 blend hydrogel. The differential scanning calorimetry results indicate that the aloe vera/F127 blend has a higher micellization temperature, affected by the lower dehydrating effect of the poly(propylene oxide) blocks during the micelle formation in comparison to F127 gel. The texture analyses (hardness and adhesiveness) showed that the addition of aloe vera gel did not change the Pluronic F127 gel texture properties. The photosensitizer zinc phthalocyanine (ZnPC) was incorporated into the aloe vera/F127 blend, and the results suggest that this formulation is suitable as a ZnPC delivery system for photodynamic therapy. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46191.
      PubDate: 2018-01-08T08:20:40.20335-05:0
      DOI: 10.1002/app.46191
  • Preparation of antibacterial and antifungal breathable polyether block
           amide/chloropropane diol membranes via- solution casting
    • Authors: Bhausaheb B. Sole; Geetha Seshadri, Ajay Kumar Tyagi, Sunita Rattan
      Abstract: A highly hydrophilic block copolymer polyether block amide (PEBA) is modified with chloropropane diol (CPD) to impart antibacterial and antifungal properties to it without compromising with its breathability. The antibacterial properties of modified membranes are evaluated against Staphylococcus aureus (S. aureus, Gram positive) and Escherichia coli (E. coli, Gram negative) bacteria by membrane culture method. CPD plays an important role in the antibacterial property with the inhibition rate reaching 99.99% for CPD modified membranes which was 27.55% and 16.82% for pristine membrane (against S. aureus and E. coli respectively). The antifungal properties studied against Aspergllus niger, Penicillium pinophilum, Aureobasidium pullulans, Chaetomium globosum, and Trichoderma virens show heavy-growth of fungi for pristine PEBA membrane while no growth was observed in case of CPD modified membranes. Breathability of membrane is determined in terms of water vapor transmission rate (WVTR) and it increase from 1496 g/m2/day to 2354 g/m2/day after modification. The membranes are characterized by FTIR-ATR, SEM-EDX, DSC, and TGA. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46097.
      PubDate: 2018-01-08T08:20:37.729494-05:
      DOI: 10.1002/app.46097
  • Design of thermosetting polymeric systems based on benzoxazines modified
           with maleic anhydride
    • Authors: Elangeni Gilbert; Graciela Morales, Marisa Spontón, Diana Estenoz
      Abstract: A novel benzoxazine (BzPFA) with carboxylic acid groups in its structure was synthesized in a two-step process. First, BzPOH monomer was obtained from bisphenol A, paraformaldehyde, and ethanolamine with an initial molar ratio 1:4:2. Then, BzPOH was reacted with maleic anhydride using a stoichiometric 1:1 ratio of oxazine ring:maleic anhydride to produce a mixture of oligomeric species named BzPFA. The products were characterized by nuclear magnetic resonance, size-exclusion chromatography, and Fourier transform infrared spectroscopy. BzPFA presented a weight-average molecular weight of 50,000 g mol−1. Mixtures of the novel precursor and the conventional benzoxazine based on bisphenol A (BzBA) (60:40 and 40:60 weight ratios) were prepared and three different curing conditions were considered in order to study the effect of BzPFA on curing and final properties. Blends exhibited improved properties respect to BzBA even at relatively low curing temperatures. These results can be associated to the network crosslinked by ester bonds that promotes a high rigidity. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46183.
      PubDate: 2018-01-08T08:20:30.716998-05:
      DOI: 10.1002/app.46183
  • Shear test method for and mechanical characteristics of short basalt fiber
           reinforced polymer composite materials
    • Authors: Jinxiang Chen; Wanyong Tuo, Chunfeng Wan, Xiaoming Zhang
      Abstract: In this work, an experimental study was performed to investigate the shearing mechanical properties of short basalt fiber-reinforced polymer composite materials (SBFRP), and an optimized test method was developed. The following findings were obtained: (1) The optimized V-notched rail shear device and test method are reliable and valid, enabling the effective shear testing of samples similar to those tested in this study in the future. (2) The shearing failure cracks of SBFRPs can be classified into three types, namely, main cracks, coupling cracks, and micro-cracks. The micro-cracks, which originate from micro-slippage at the interfaces between the short fibers and the epoxy resin, initiate prior to the main cracks. (3) The existence of a critical value of the fiber volume fraction is proposed, above which a sample possesses a nonlinear deformation capacity by virtue of the initial micro-slippage at the fiber/matrix interfaces. Furthermore, a higher fiber volume fraction gives rise to a stronger nonlinear deformation capacity. (4) The shearing mechanical properties and other basic material attributes of SBFRPs with a fiber length of 3 mm are presented, thereby establishing a foundation for the theoretical study, finite-element analysis, and application and dissemination of SBFRPs. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46078.
      PubDate: 2018-01-05T07:01:17.108182-05:
      DOI: 10.1002/app.46078
  • Ternary proton exchange membranes with low-cost raw materials: Solvent
           type influence on microstructure development, high ionic conductivity, and
           ionic liquid lixiviation protection
    • Authors: Jose Jonathan Rubio Arias; Ailton de Souza Gomes
      Abstract: A critical stage of solvent evaporation during membrane casting was identified as responsible for significant differences in performance of ternary membranes composed of PEEK with 73% of sulfonation degree. DemaTfO and MmtdemaDMF showed to be the best solvent for casting of membranes prepared through the present study, which is against the observations made through other different studies. Fractal structures are formed regardless of solvent polarity, and interlamellar spacing is found to be higher when DMF is used, which led to higher conductivity and IL leaching protection. Proton relaxometry showed that only the membranes made with DMF and DMAc possess one single mobility domain. Transmission electron microscopy micrographs showed a higher damage in membranes with two different mobility domains and consequent phase separation. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46012.
      PubDate: 2018-01-05T02:42:57.788595-05:
      DOI: 10.1002/app.46012
  • Single fiber peel test to assess ultra high molecular weight polyethylene
           fiber mesostructure interactions
    • Authors: Preston B. McDaniel; Joseph M. Deitzel, Domenick Gregory, Timothy Polakovic, John W. Gillespie
      Abstract: In this work, a variable angle, single fiber peel test is developed to analyze the effects of fiber structure on the mixed mode failure within ultra high molecular weight polyethylene fibers. The Mode I and Mode II peel energy release rates are quantified and the effects of fiber meso/nanostructure on these modes are examined. Comparison of the load-extension curves from the peel test with in-situ video, and post-mortem analysis using high-resolution microscopy techniques indicates that Mode I and Mode II splitting are both significantly influenced by the deformation of nanoscale fibrils within a mesoscale network. The fibrils in the network are placed in tension across the peel/shear interface resulting in elevated values of peel energy release rates with an increasing number of engaged fibrils. The number of engaged fibrils is shown to increase with decreasing peel angle and increasing Mode II failure contribution. A bi-linear mixed-mode failure criterion is established. The results, and analysis of the fiber structure are discussed in context of their implications for load pathways in the fiber. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46156.
      PubDate: 2018-01-05T02:42:36.119873-05:
      DOI: 10.1002/app.46156
  • Looking back to interfacial tension prediction in the compatibilized
           polymer blends: Discrepancies between theories and experiments
    • Authors: Farzaneh Hassanpour Asl; Mohammad Reza Saeb, Seyed Hassan Jafari, Hossein Ali Khonakdar, Hadi Rastin, Petra Pötschke, Roland Vogel, Florian J. Stadler
      Abstract: Prediction of interfacial tension of compatibilized polymer blends is a challenging open problem, where experiments and theories hardly support each other. In this work, constitutive models proposed for quantifying the interfacial tension of compatibilized polymer blends were revisited and their limitations/capabilities were discussed. In view of available data in the literature, which could provide with possibility of comparison between interfacial tension values obtained in this work and those published before, high-density polyethylene (HDPE)/polyamide-6 and HDPE/polyethylene-co-vinyl alcohol pairs comprising varying amounts of HDPE-g-maleic anhydride compatibilizer precursor were prepared for obtaining model parameters. The inability of theories in monitoring the interfacial tension was accordingly uncovered. However, outcomes from both theoretical and experimental data provided some insights for elucidating the interplay between interfacial tension and rheological characteristics of the studied compatibilized blends. It was also attempted to uncover the relationships between particle size, particle size distribution, and rheological properties of blends compatibilized with different amounts of HDPE-g-maleic anhydride precursor. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46144.
      PubDate: 2018-01-05T02:41:54.245428-05:
      DOI: 10.1002/app.46144
  • Effect of block copolymer containing ionic liquid moiety on interfacial
           polarization in PLA/PCL blends
    • Authors: Ping Wang; Pei Xu, Haibing Wei, Huagao Fang, Yunsheng Ding
      Abstract: Compared with poly(ɛ-caprolactone)-b-poly(ethylene glycol) block copolymer (BC), a systematic study of the effect of the concentration of the compatibilizer, poly(ɛ-caprolactone)-b-poly(ethylene glycol) BC containing ionic liquid moiety (BCIL), on the interfacial properties of a phase separating blend of poly(l-lactic acid)/poly(ɛ-caprolactone) (PLA/PCL) was performed. BCIL copolymer as a compatibilizer for immiscible PLA/PCL blend can reinforce the interactions between the two polymeric phases by the IL electrostatic interaction at interphase, and the particle size of PCL decreases because of interfacial reinforced-compatibilization of IL moiety. Ion mobility of IL moiety at interphase and PCL phase for PLA/PCL/BCIL blend can induce interfacial blocking of charge carriers, and IL moiety segregating mainly at the interface can decrease the relaxation rate and increase the dielectric strength of interfacial polarization. Our results provide a methodology to characterize and tune the morphology and blocking of charge carriers with the aim of tailoring the dielectric interfacial properties of blends. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46161.
      PubDate: 2018-01-05T02:41:39.225127-05:
      DOI: 10.1002/app.46161
  • Preparation of silica/poly(styrene-co-butyl acrylate) core/shell composite
           particles for absorption of toluene
    • Authors: Xiaojie Dong; Xiao Li, Zhenpeng Xie, Sen Weng, Weiying Zhang, Xiaoguang Ying
      Abstract: An absorbent for benzene series with silica/poly(styrene-co-butyl acrylate) core/shell structure was prepared via emulsion polymerization. The effects of emulsifier dosage, monomer concentration, and crosslinker dosage on the absorption of the core/shell composite particles were investigated. The composite particles with good absorbency could be obtained when the emulsifier concentration was 2.5 g/L, monomer concentration was 40 g/L, crosslinker dosage was 2.0% (based on the total mass of the monomer), and the initiator dosage was 1.0%. The composite particles exhibited a rapid absorption and the absorption process conformed to the quasi-second order kinetics. Fourier-transform infrared spectroscopy, scanning electron microscope, and energy dispersive spectrometer (EDS) showed the presence of copolymer layer on the surface of silica. The work provided a new path to fabricate novel composite absorbent particles for a wide range of applications. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46172.
      PubDate: 2018-01-05T02:41:28.413244-05:
      DOI: 10.1002/app.46172
  • Synthesis and characterization of poly(aminobismaleimide)s obtained from
           solvent-free mixtures
    • Authors: Arnaud Soisson; Linda Chikh, Philippe Banet, Jean-Michel Morelle, Odile Fichet
      Abstract: A series of eight poly(aminobismaleimide)s containing aromatic units have been synthesized from a one-step nucleophilic addition reaction between diamine and bismaleimide, without exogeneous solvent, to provide encapsulant withstanding high temperature suitable for power electronics. To have a homogeneous medium at room temperature, the solid aromatic diamines are first mixed with different liquid aliphatic ones, and then mixed with bismaleimide. The syntheses were then carried out at 175 °C for 15 min. Thus, according to their composition, these obtained thermosetting resins are characterized by a relaxation temperature between 98 and 190 °C and a coefficient of thermal expansion between 20 and 150 ppm/K. All material surfaces are hydrophobic and their moisture uptake is lower than 2–3 wt %. Finally, as expected, the substitution of a part of the aliphatic diamine by an aromatic one improves the thermal stability under air atmosphere of the resulting materials (Td = 280–300 °C increased to Td = 315–340 °C). Their use as power module encapsulant can therefore be considered. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46105.
      PubDate: 2018-01-05T02:41:08.511353-05:
      DOI: 10.1002/app.46105
  • Synthesis of a phosphorus- and nitrogen-containing flame retardant and
           evaluation of its application in waterborne polyurethane
    • Authors: Shuang Wang; Zongliang Du, Xu Cheng, Yuansen Liu, Haibo Wang
      Abstract: A phosphorus- and nitrogen-containing intumescent flame retardant, pentaerythritol di-N-hydroxyethyl phosphamide (PDNP), was synthesized with phosphorus oxychloride, pentaerythritol, and ethanolamine as raw materials. Using the prepared PDNP as a chain extender, a series of flame-retardant waterborne polyurethanes (WPU) were prepared, and their structures were characterized using NMR and Fourier transform infrared spectroscopy (FTIR). Additionally, the thermal properties and flame retardancy of WPU films were investigated by thermogravimetric analysis, limiting oxygen index (LOI) tests, cone calorimeter tests, and thermogravimetry-FTIR. These results indicated that PDNP materials exhibit good char-forming ability at high temperature and that PDNP-modified waterborne polyurethane obtained an LOI value of 26.0% for a PDNP content of 9 wt %. Finally, the morphology and the element distributions of char residues of WPU were analyzed by scanning electron microscopy and energy dispersive spectrometry after combustion. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46093.
      PubDate: 2018-01-03T11:10:52.542873-05:
      DOI: 10.1002/app.46093
  • Preparation of a novel styrene copolymer: Simultaneously improving the
           thermal stability and toughness
    • Authors: Jianguang Cui; Changjiang Zhu, Mingshan He, Zhenkun Ke, Yu Liu, Qilong Tai, Xifu Xiao, Yuan Hu
      Abstract: In order to improve the flame retardancy of polystyrene, a phosphorus- and nitrogen-containing monomer, N,N-tetramethyl-bis(phospohonate)-2-hydroxyethyl bis(methylene) amine acrylate (BC2NP2), was synthesized and characterized, and then incorporated into various amounts of polystyrene via radical emulsion copolymerization. The copolymers prepared were characterized by Fourier transform infrared, nuclear magnetic resonance spectra, transmission electron microscopy, differential scanning calorimetry, thermalgravimetric analysis, microscale combustion calorimeter, dynamic mechanical analysis, and impact tests. The results showed that all the copolymers had well spherical core–shell structure. Notably, despite a few amounts of the BC2NP2 units in copolymers, all the copolymers exhibited significantly enhanced thermal stability, decreased glass transition temperature, and reduced flammability. Furthermore, from dynamic mechanical analysis and impact tests, it was observed the storage modulus was decreased and the impact strength had a certain degree of improvement with the incorporation of commoner. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46120.
      PubDate: 2018-01-03T11:08:13.068264-05:
      DOI: 10.1002/app.46120
  • Preparation and electrochemical properties of polyaniline/reduced graphene
           oxide composites
    • Authors: Yunlong Li; Yuying Zheng
      Abstract: Polyaniline (PANI)/reduced graphene oxide (rGO) composites were synthesized by in situ oxidative polymerization of aniline on reduced graphene sheets. Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, transmission electron microscopy, and scanning electron microscopy were used to characterize the composites. The results indicated PANI/rGO composites were produced and contained covalent bonds between the functional groups of PANI and rGO. A uniform coating of PANI on the rGO sheets had a synergistic effect on the properties of the composites. The electrochemical properties of the PANI/rGO composites produced using different feed ratios of aniline to rGO were studied. The results showed that the composites exhibited a maximum specific capacitance of 797.5 F/g at 0.5 A/g and minimum charge transfer resistance of 0.98 Ω when the feed ratio of aniline to rGO was 2:1. These values were superior to those of pure PANI and rGO. The composites also displayed excellent cycling stability, with specific capacitance retention of 92.43% after 1000 cycles. These stable structural composites show promise for the development of new supercapacitor applications. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46103.
      PubDate: 2018-01-03T11:08:03.07624-05:0
      DOI: 10.1002/app.46103
  • Effect of polyurethane sizing on carbon fibers surface and interfacial
           adhesion of fiber/polyamide 6 composites
    • Authors: Tao Zhang; Yueqing Zhao, Hongfu Li, Boming Zhang
      Abstract: Commercial epoxy sized carbon fibers (CFs) or unsized CFs have poor interfacial adhesion with polyamide 6 (PA6). Here, CFs are coated with polyurethane (PU) and their surface properties in terms of surface chemistry, contact angle, roughness, and morphology, are investigated. The results of Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and atomic force microscopy demonstrate PU sizing evidently increases the quantity of polar functional groups on the CFs surface. The surface energy of the PU sized fiber is calculated according to the Owens–Wendt method. Compared with unsized fibers, the contact angle of PU sized fibers is decreased while their total surface energy is increased, indicating superior wettability. Moreover, transverse fiber bundle tests are performed to determine the interfacial adhesion between the CFs and PA6 matrix. The transverse fiber bundle strength of unsized CF is measured to be 12.57 MPa. For PU sized CFs processed with sizing concentration of 1.2%, this value is increased to 24.35 MPa, showing an increase of more than 90%. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46111.
      PubDate: 2018-01-03T11:07:56.504289-05:
      DOI: 10.1002/app.46111
  • Garlic oil–loaded PLGA nanoparticles with controllable size and shape
           and enhanced antibacterial activities
    • Authors: Sherif Ashraf Fahmy; Wael Mamdouh
      Abstract: The present work focuses on producing polymer composite nanoparticles (NPs) composed of garlic oil (GO) and poly(lactic-co-glycolic) acid (PLGA) by the single emulsion/solvent evaporation (SE/SE) method and high-speed homogenizing. Different preparation parameters were found to greatly affect the stability and size uniformity of the prepared PLGA/GO NP formulations, which were carefully controlled. Scanning electron microscopy, Fourier transform infrared spectroscopy, and UV–vis spectroscopy and dynamic light scattering and zeta potential were used to characterize the NPs. Antibacterial assessment of the prepared PLGA/GO NPs against E. coli and S. aureus was carried out. Interestingly, the NP size ranged between 201 and 319 nm, which is 10 times less than the size of the regular GO particles in bulk solution. The antibacterial activities show enhancement by 70–78% of bacterial inhibition compared with a GO bulk solution. This work sheds light on the potential use of GO NP formulations as nanobiotics and the critical NP preparation parameters that need to be considered. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46133.
      PubDate: 2018-01-03T11:07:50.25189-05:0
      DOI: 10.1002/app.46133
  • Effect of interface on the mechanical behavior of polybutadiene–silica
           composites: An experimental and simulation study
    • Authors: Tuo Ji; Chi Ma, Logan Brisbin, Yalin Dong, Jiahua Zhu
      Abstract: The effect of interface property on the mechanical behavior of silica–polybutadiene composites is systematically investigated via combined experimental and dynamics simulation. In experiment, the interface property is controlled by SiO2 particle size, silane coupling agents, and silane grafting density. The effects of these control parameters on the vulcanization kinetics, tensile strength, and dynamic mechanic properties are investigated and discussed. Both the experimental and simulation studies reveal the pivot role of filler–polymer interface on the mechanical reinforcement. Simulation study reveals that the constrained polymer layer (∼12 nm) surrounding the silica particles shows increased stress from 30 to 230 MPa, which is identified as the major reason for the overall enhancement of 100% modulus from 0.8 to 1.6 MPa. The molecular mechanics of interface from simulation is well correlated to the experimental results in this study, which provides a molecular level understanding of the relationship between interfacial interaction and mechanical reinforcement. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46089.
      PubDate: 2018-01-03T05:01:30.338489-05:
      DOI: 10.1002/app.46089
  • Kinetics of chitosan coagulation from aqueous solutions
    • Authors: Alin Alexandru Enache; Laurent David, Jean-Pierre Puaux, Ionut Banu, Grigore Bozga
      Abstract: In this study, we investigated the kinetics of chitosan hydrogel formation from aqueous chitosan solutions with sodium hydroxide (NaOH) as the coagulant. Two sets of experiments were performed, one in a parallelepiped cell and the other with cylindrical chitosan solution extrudates. The coagulation occurred by the neutralization of the protonated amino groups (NH3+) present in the chitosan chains, with the kinetics being controlled by NaOH transport toward the gelification zone. In this study, we confirmed the appropriateness of Fick's second law to describe NaOH transport, considering the instantaneous reaction between the NaOH and NH3+ groups. The experimental data were used to determine the NaOH diffusion coefficient in gels having different chitosan concentrations. The diffusion coefficient values obtained from the cylindrical coagulation data were lower than those determined for linear coagulation because of the influences of transport geometry and gel structure, respectively. Accordingly, in fiber coagulation calculations, it is recommended to use diffusion coefficient values determined from cylindrical coagulation studies. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46062.
      PubDate: 2018-01-03T05:00:53.04787-05:0
      DOI: 10.1002/app.46062
  • Effective removal of a cobalt-tetrasulfonated phthalocyanine dye from an
           aqueous solution with a novel modified chitosan-based superabsorbent
    • Authors: Ali Reza Karimi; Bahare Rostaminezhad, Azam Khodadadi
      Abstract: Industrial wastewaters from the Merox process are heavily polluted by toxic cobalt-tetrasulfonated phthalocyanine (CoTsPc) dye catalyst, and in this article, we describe the synthesis of novel chitosan hydrogels and their adsorption capabilities against CoTsPc as biosorbents. In this study, novel chitosan hydrogels were crosslinked by 3,3′,4,4′-tetracarboxybenzophenone dianhydride and used for the first time. The adsorption capacities of the hydrogels were significantly improved, and they exhibited excellent sorption behavior with ammonium sulfate modification. The adsorption behavior was observed to be pH dependent, and the optimum pH was found to be 8. Moreover, the swelling studies indicated that the hydrogels are superabsorbent. The reusability of these dye-adsorbent hydrogels was also evaluated. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46167.
      PubDate: 2017-12-29T03:31:56.540484-05:
      DOI: 10.1002/app.46167
  • Influence of processing conditions on mechanical properties of blends of
           styrenic block copolymer and poly(phenylene oxide): Miscibility and
           microdomain size
    • Authors: Xiangtian Yu; Xiang Wang, Aiming Zhang, Tao Zhou
      Abstract: The effect of processing conditions on mechanical properties of poly(styrene-b-ethylene-co-butylene-b-styrene) (SEBS) and poly(2,6-dimethy-1,4-phenylene oxide) (PPO) blends were investigated. Differential scanning calorimetry and small angle X-ray scattering were used to study the miscibility and d-spacing of the blends. The processing temperature plays an important role in mechanical properties. PPO works as filler and weakens mechanical properties when the processing temperature is below 230 °C. As the processing temperature exceeds 230 °C, PPO incorporates into the PS blocks of SEBS and the performance enhances with increasing temperature due to a better miscibility. The strong shear stress is beneficial to the dispersion of PPO into SEBS matrix and more PPO incorporates into PS blocks during melt processing, resulting in the better mechanical properties and a larger d-spacing. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46123.
      PubDate: 2017-12-29T03:31:39.723559-05:
      DOI: 10.1002/app.46123
  • Thermal and mechanical properties of tetra-functional mesogenic type epoxy
           resin cured with aromatic amine
    • Authors: Miyuki Harada; Daichi Morioka, Mitsukazu Ochi
      Abstract: A novel tetra-functional epoxy monomer with mesogenic groups was synthesized and characterized by 1H-NMR and FTIR. The synthesized epoxy monomer was cured with aromatic amine to improve the thermal property of epoxy/amine cured system. The glass transition temperature (Tg) and coefficient of thermal expansion (CTE) of the cured system were investigated by dynamic mechanical analysis and thermal mechanical analysis. The properties of the cured system were compared with the conventional bisphenol-A type epoxy and mesogenic type epoxy system. The storage modulus of the tetra-functional mesogenic epoxy cured systems showed the value of 0.96 GPa at 250 °C, and Tg-less behavior was clearly observed. The cured system also showed a low CTE at temperatures above 150 °C without incorporation of inorganic components. These phenomena were achieved by suppression of the thermal motion of network chains by introduction of both mesogenic groups and branched structure to increase the cross linking density. The temperature dependency of the tensile property and thermal conductivity of the cured system was also investigated. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 135, 46181.
      PubDate: 2017-12-29T03:31:20.282852-05:
      DOI: 10.1002/app.46181
  • Reusable magnetic nanocluster coated with poly(acrylic acid) and its
           adsorption with an antibody and an antigen
    • Authors: Siraprapa Meerod; Nunthiya Deepuppha, Boonjira Rutnakornpituk, Metha Rutnakornpituk
      Abstract: The synthesis of negatively charged magnetite nanoclusters grafted with poly(acrylic acid) (PAA) and their application as reusable nanosupports for adsorption with antibodies and antigens are presented in this article. They were facilely prepared via the free-radical polymerization of PAA in the presence of functionalized magnetite nanoparticles to obtain highly negative charged nanoclusters with a high magnetic responsiveness and good dispersibility and stability in water. According to transmission electron microscopy, the sizes of the nanoclusters ranged between 200 and 500 nm, without large aggregation visually observed in water. The hydrodynamic size of the nanocluster consistently increased with increasing pH of the dispersion; this indicated its pH-responsive properties, which was due to the repulsion of the anionic carboxylate groups in the structure. This nanocluster was successfully used as an efficient and reusable support for adsorption with anti–horseradish peroxidase antibody. It preserved higher than a 97% adsorption ability of the antibody after eight reuse cycles; this signified the potential of this novel nanocluster as a reusable support in the magnetic separation applications of other bioentities. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 135, 46160.
      PubDate: 2017-12-29T03:31:17.158003-05:
      DOI: 10.1002/app.46160
  • Influence of surface properties on the dip coating behavior of hollow
           fiber membranes
    • Authors: Isabel Jesswein; Sarah Uebele, Alina Dieterich, Silke Keller, Thomas Hirth, Thomas Schiestel
      Abstract: Coating processes have become an important fabrication step in membrane production, either to form a separation layer on a porous substrate or to tune specific properties. The coating procedure depends to a large extent on the membrane properties which substantially impedes a prediction of the coating thickness. To give an insight into the coating properties of various hollow fiber membranes, a selection of membranes with different pore sizes was coated with aqueous poly(vinyl alcohol) solutions at various coating velocities. It was found that material properties and pore sizes of the membranes have great influence on coating thicknesses. An intrusion of coating material into the membrane structure was determined with increasing pore size. Pure intrusion without formation of a dense surface layer took place when using a membrane with a mean pore size of ca. 500 nm. Coating results were correlated with the theoretical LLD law and for some membranes the coating thickness can be predicted quite well by the LLD law and its enhancements. When a significant amount of coating material penetrated into the membrane structure the LLD law loses its validity. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 135, 46163.
      PubDate: 2017-12-29T03:30:46.452753-05:
      DOI: 10.1002/app.46163
  • Hierarchical structure and properties of rigid PVC foam crosslinked by the
           reaction between anhydride and diisocyanate
    • Authors: Zhiwei Jiang; Zhonghui Du, Jian Xue, Wenbin Liu, Minggang Li, Tao Tang
      Abstract: Rigid crosslinked poly(vinyl chloride) (c-PVC) foams by forming semi-interpenetrating network (SIPN) structure via the reaction of phthalic anhydride (PA) and diisocyanate were prepared. The influence of PA on hierarchical structure and mechanical properties of c-PVC foam was studied. The Fourier transform infrared spectrometer results showed that the presence of PA resulted in the formation of imide structure in the SIPN of obtained c-PVC foams, which introduced a structural defect of SIPN. Thus, the residue (gel) from tetrahydrofuran extraction of the foams decreased with the increase of PA content. Dynamic thermal analysis showed the presence of three aggregation state structures in the c-PVC foams, depending on the loading of PA. The addition of PA in the formulations affected cellular structure and mechanical properties of the obtained foams. Furthermore, the influence of chemical environment of anhydride compounds on the formation of imide structure in the crosslinking network of c-PVC foams was discussed. A strategy for reducing defect of crosslinking network and improving mechanical properties was put forward. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46141.
      PubDate: 2017-12-29T03:30:37.259009-05:
      DOI: 10.1002/app.46141
  • Editorial Board, Aims & Scope, Table of Contents
    • PubDate: 2017-12-28T08:35:57.288467-05:
      DOI: 10.1002/app.45594
  • Cover Image, Volume 135, Issue 14
    • Abstract: Hybridized nanoparticle strategy for graphene oxide based materials can effectively improve the mechanical property of their nanocomposites. Silica nanoparticles have a spherulite-like morphology, which can absorb on the surface of graphene oxide (layered morphology) under suspension solution system. In this study by Masoud Jamshidi and colleagues, the Ruoff phenomenon indicates that nanoparticles with different dimensions can improve dispersion of each other in polymers and enables the graphene oxide to disperse in nitrile rubber, thus improving the mechanical property and rubber elasticity. (
      DOI : 10.1002/app.46091).
      PubDate: 2017-12-28T08:35:48.809738-05:
  • Polysulfobetaine bearing tertiary amide between counterions and its
    • Authors: Vivek Arjunan Vasantha; Algin Oh Biying, Anbanandam Parthiban
      Abstract: Modified sulfobetaine bearing tertiary amide spacer between the counterions is synthesized and polymerized by reversible addition–fragmentation chain transfer polymerization technique. The tertiary amide spacer influences various characteristics of the zwitterionic polymer. The modified polyzwitterion, PZI, forms coacervates in deionized water. The coacervates are thoroughly characterized by scanning electron microscopy, transmission electron microscopy, and transmittance studies. The ability to form coacervate complexes with functional ingredients has been demonstrated by encapsulating renewable resource actives like ferulic acid. The coacervate complexes have been studied by optical microscopy, transmission electron microscopy, and automated sunscreen sun protection factor analyzer. Synergism is noticed in the coacervate complex. Because of its ability to form self-coacervates, this novel addition to the zwitterionic family is potentially useful for encapsulating many functional ingredients through coacervate complex formation. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 135, 46178.
      PubDate: 2017-12-28T06:22:13.837185-05:
      DOI: 10.1002/app.46178
  • UV and corrosion protective behavior of polymer hybrid coating on mild
    • Authors: I. Pugazhenthi; S. Mohammed Safiullah, K. Anver Basha
      Abstract: Poly((pyridine-4-yl-methyl)methacrylate-co-butyl methacrylate) (Poly(PyMMA-co-BMA)) and its ZnO nanocomposites (Poly(PyMMA-co-BMA)/ZnO) were coated on the mild steel substrate (MS) to improve the corrosion resistance by blocking the destructive ultraviolet radiation (UV-radiation) and corrosive ions as well. The optical and anticorrosive properties of Poly(PyMMA-co-BMA) and Poly(PyMMA-co-BMA)/ZnO (1.0, 1.5, and 2.5 wt %) coatings were evaluated. The surface characterization techniques like UV visible spectroscopy and scanning electron microscope were taken to confirm the formation of Poly(PyMMA-co-BMA) and Poly(PyMMA-co-BMA)/ZnO (2.5 wt %) coating on MS. The optical studies revealed that the Poly(PyMMA-co-BMA)/ZnO (2.5 wt %) coating displays excellent UV blocking properties than other nanocomposite coatings (1.0 and 1.5 wt %). The potentiodynamic polarization and electrochemical impedance spectroscopy studies show that the Poly(PyMMA-co-BMA) and Poly(PyMMA-co-BMA)/ZnO (1.0, 1.5, and 2.5 wt %) coated MS in 3.5% (w/v) NaCl provides better protection against corrosion. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46175.
      PubDate: 2017-12-28T06:22:04.263458-05:
      DOI: 10.1002/app.46175
  • Investigation of dielectric properties of free standing electrospun
           nonwoven mat
    • Authors: Jitendra Tahalyani; Suwarna Datar, Balasubramanian Kandasubramanian
      Abstract: Flexible materials with balanced dielectric as well as conductive characteristics have elucidated considerable demand in field of research where conventional dielectric or insulators can be replaced by recent advances in various electronics appliances. Our work describes the detailed analyses of dielectric properties like dielectric constant, losses, and electric modulus by means of broadband dielectric spectroscopy over frequency ranging from 0.1 Hz to 10 MHz and temperature ranging from 0 to 60 °C for poly(vinyl alcohol)-polyaniline (PVA-PANI) free standing electrospinning nonwoven mat. It has been contemplated that the dielectric constant was enhanced by increasing PANI concentration for complete range of frequency at room temperature. The enhanced dielectric constant value (5.14 at 0.1 Hz, 2.66 at 1 KHz, 2.58 at 10 KHz, and 2.19 at 10 MHz) was anticipated for 7 wt % loading of PANI which was attributed to the presence of dipoles and interfacial polarization enclosed by the polymers. The increased dielectric constant with PANI dosing as well as with temperature attributed to favorable interfacial polarization. Shifting of peak is noticed in the spectra of imaginary electric modulus with increase in temperature which indicates increased chain dynamics of polymers in the mat. Three-dimensional analysis of the field emission scanning electron microscopy images was carried out by SPIP analytical software. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 135, 46121.
      PubDate: 2017-12-28T06:21:55.866455-05:
      DOI: 10.1002/app.46121
  • Electrospun poly(vinyl alcohol)/permutite fibrous film loaded with
           cinnamaldehyde for active food packaging
    • Authors: Ping Shao; Zhipeng Yan, Hangjun Chen, Jie Xiao
      Abstract: Electrospun ultra-fine poly(vinyl alcohol)/permutite fibrous film loaded with cinnamaldehyde essential oil was successfully fabricated.The morphology of fibrous filmswas characterized by scanning electron microscopy (SEM) and atomic force microscope (AFM). The fibrous film exhibited microstructure features with high porosity with the pore size distributed ranging from 1.7 nm to 56.7 nm. And the root-mean-squared roughness of fibers lifted to 546.5 nm when the addition of cinnamaldehyde essential oil (CEO) reached 0.25 mL. Attenuated total reflectance-fourier transform infrared (ATR-FTIR) spectroscopyconfirmed the existence of CEO in fibrous films and revealed physical interaction rather than chemical interactions existing between the film matrix and CEO. Endothermic peaks presented in differential scanning calorimetry (DSC) profile were probably rooted from existed mesoporous adsorption between the highly porous film matrix and CEO. Furthermore, the PVA/permutite/CEO fibrous film prolonged the shelf life of strawberries, confirming that the PVA/permutite/CEO fibrous film may be of interest for the development of active food packaging. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46117.
      PubDate: 2017-12-28T06:21:49.612962-05:
      DOI: 10.1002/app.46117
  • Investigations on matrix network characteristics in NBR/silica
           nanocomposites: Resolving matrix bulk density and network molecular weight
           and their alterations due to filler-curing agent interactions
    • Authors: Mohammad Khabiri; Seyed Hassan Jafari, Mohammad Reza Pourhossaini, Hossein Ali Khonakdar
      Abstract: Presence of filler in an elastomeric composite can affect curing characteristics due to possible interaction with curing agents. Alteration of the curing characteristics can change intrinsic properties of elastomer including its bulk density and swelling behavior. In this study, a series of acrylonitrile butadiene rubber (NBR) with various curing levels was prepared. From the experimental data the bulk density and network molecular weight (Mc,sw) were specified and a relationship was established between these parameters. In order to determine the swelling characteristics of NBR in presence of filler, another series of NBR/silica nanocomposites was prepared with various nanosilica loadings under a constant content of curing agents and curing conditions. With the use of the swelling data and applying the obtained relationship, the Mc,sw and bulk density of the filled NBR matrix were resolved. The Mc,sw values obtained by considering the influence of nanosilica on curing characteristics of NBR were compared with those obtained simply based on bulk density of raw rubber. This comparison confirmed that there are considerable differences between these values. With increasing nanosilica contents, and hence, increasing the negative impact of the filler on reducing curing degree of NBR, the bulk density of filled NBR matrix was decreased. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 135, 46170.
      PubDate: 2017-12-28T06:21:34.822458-05:
      DOI: 10.1002/app.46170
  • The use of noncovalently modified carbon nanotubes for preparation of
           hybrid polymeric composite materials with electrically conductive and
           lightning resistant properties
    • Authors: Stanislav V. Kondrashov; Mikhail A. Soldatov, Anna G. Gunyaeva, Konstantin A. Shashkeev, Olga A. Komarova, Dmitriy Y. Barinov, Gleb Y. Yurkov, Vitaliy G. Shevchenko, Aziz M. Muzafarov
      Abstract: In this work, approach to use of noncovalently modified carbon nanotubes is given for preparation of functional hybrid polymeric composite materials (HPCM) based on epoxy resin. Conductive glass-fiber plastics with resistivity in transverse and lengthwise direction 9.0·× 102 and 30–50 Ohm cm, respectively, were obtained. The tetrafluoroethylene telomer and fluorocontaining organosilicon copolymer with amino groups were used as modifiers for carbon nanotubes. Thermal, electrical, and mechanical properties of the obtained materials were studied. The mechanism of the effect of noncovalent modification of carbon nanotubes on functional properties of HPCM was discussed. It was found, that type of modifier significantly affects the level of functional properties. The use of fluorocontaining organosilicon copolymer is more optimal in comparison with tetrafluoroethylene telomer. Thus, HPCM with carbon-fiber filler and this modifier has higher electrical conductivity and lightning strike resistance in comparison with nonmodified HPCM. This approach is promising to impart antistatic properties for glass-fiber plastics and increase lightning resistance of carbon-fiber plastics. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46108.
      PubDate: 2017-12-28T06:21:25.986138-05:
      DOI: 10.1002/app.46108
  • Hydrophobic properties of poly(arylene ether)s derived from linear
           polydimethysiloxanes and decafluorobiphenyl
    • Authors: Xinqi Lin; Xuesong Li, Jinmeng Hao, Xuan Zhao, Yanfeng Wei, Jianxin Mu
      Abstract: A series of novel poly(arylene ether)s were synthesized with diphenol liner polydimethysiloxanes with different silicon numbers (2OH-PDMS-P; P = 2, 6, 10, 12, 16) and decafluorobiphenyl via a two-step nucleophilic substitution polymerization. The chemical structures of the polymers were confirmed by Fourier transform infrared spectrometer, 19F-NMR and 1H-NMR spectra. All the polymers provided outstanding hydrophobic properties, high thermal stability and good solubility. The water contact angle (WCA) first increased and then suddenly decreased with the increasing of silicon numbers in PDMS. The highest WCA about 112° was obtained when silicon numbers was ten. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 135, 46187.
      PubDate: 2017-12-28T06:21:16.766148-05:
      DOI: 10.1002/app.46187
  • High bonding strength and boiling water resistance of soy protein-based
           adhesives via organosilicon–acrylate microemulsion and epoxy synergistic
           interfacial enhancement
    • Authors: Shujun Zhao; Fangru Xing, Zhong Wang, Haijiao Kang, Shifeng Zhang, Jianzhang Li
      Abstract: Boiling water resistance, an important indicator of wood adhesives, represents the capability of adhesives for exterior woodwork applications. However, soy-based adhesives show poor behaviors in this respect, which limit their applications in outdoor environments. In this article, we report a synergistic modification method of integrating a cocrosslinking system of epoxied polyamideamine-epichlorohydrin (PAE) and organosilicon–acrylate copolymer latexes (OACLs) to improve soybean meal (SM)-based adhesive properties. Tailored PAE and OACL SM-based adhesives demonstrated robust crosslinking structures via multi-interfacial interactions, where PAE and OACL served as building blocks of an interpenetrating network, which was characterized by Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, and scanning electron microscopy. The dry-shear strength, wet-shear strength, and boiling water strength of the resulting SM-based adhesives were 1.41 ± 0.13, 1.32 ± 0.17, and 1.20 ± 0.11 MPa, respectively, with 15 wt % OACL loading; these were 41, 45, and 90% increases, respectively, over the SM–PAE adhesive with which we compared them. Most importantly, the excellent boiling water resistance of the adhesives make them practical for exterior plywood. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 135, 46061.
      PubDate: 2017-12-28T06:20:54.649881-05:
      DOI: 10.1002/app.46061
  • Chemical curing of alkyd resin catalyzed by benzoylferrocene: Performance,
           kinetics, and thickness effects
    • Authors: Jan Honzíček; Jaromír Vinklárek
      Abstract: Catalytic properties of benzoylferrocene, as a representative of cobalt-free drier, was investigated on alkyd resin modified with soybean oil. Mechanical tests, performed on alkyd films, revealed promising activity at low metal concentrations. A detailed analysis of time resolved infrared spectra was used for in-depth investigation of chemical curing in the films. The experiments, performed in transmission mode, enabled determination of kinetic parameters for the autoxidation process. Effects of film thickness were investigated using attenuated total reflectance technique. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 135, 46184.
      PubDate: 2017-12-28T06:20:50.319228-05:
      DOI: 10.1002/app.46184
  • Polymer adhesion in heat-treated nonwovens
    • Authors: Christopher Staszel; Alexander L. Yarin, Behnam Pourdeyhimi
      Abstract: Polymer adhesion and sintering in compound nonwovens was studied. Nonwovens containing a mixture of binding bi-component (BICO) fibers embedded in a fibrous matrix were heated to melt the outer shell of BICO fibers and interlock the matrix to create stiff load-bearing surfaces. It was found that stiffness depends on heat-treatment regimes. In low-temperature regimes, BICO fibers melt, but do not fully flow and encase the surrounding filler matrix. At sufficiently high temperatures, the shells of BICO fibers melt and flow which results in encasing the neighboring filler fibers. This results in an abrupt increase in the nonwoven stiffness which is independent of heat-treatment temperature. At significantly high temperatures, the filler matrix fibers sinter to each other leading to a further increase in stiffness. The experiments were conducted with co-polymers frequently used in the shells of BICO to demonstrate the interlocking mechanism characteristic of these compound nonwovens. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 135, 46165.
      PubDate: 2017-12-27T06:57:05.177671-05:
      DOI: 10.1002/app.46165
  • Fabrication of a fast-swelling superabsorbent resin by inverse suspension
    • Authors: Jinxia Li; Kuihua Zhang, Mengyi Zhang, Yu Fang, Xiaofeng Chu, Lu Xu
      Abstract: A novel, fast-swelling superabsorbent polymer (SAP2) was fabricated with an anionic–nonionic surfactant [poly(oxy-1,2-ethanediyl)–(3-carboxy-1-oxo-3-sulfopropyl)–(nonylphenoxy) sodium salt] as the stabilizer by inverse suspension polymerization. The microstructure, chemical structure, and gel strength of the superabsorbent polymers (SAPs) were characterized by scanning electron microscopy, porosity, and specific surface area analysis, Fourier transform infrared spectroscopy, and rheometry. The results show that SAP2 had irregularly shaped particles with a large number of pores and presented a greater specific surface area, pore volume, and gel strength than the prepared SAP1 with a nonionic surfactant (Span 60) as the stabilizer. The amount of residual monomer and the gel fraction of SAP2 were 202 mg/kg and 80.6%, respectively. Meanwhile, SAP2 demonstrated a faster swelling and deswelling rate as well as greater water absorbency than SAP1. The fast swelling rate mainly resulted from the capillary effect of the pores in the irregularly shaped particles. Superfast swelling SAPs should possess outstanding potential for healthcare products, communication cables, and the biomedical field. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 135, 46142.
      PubDate: 2017-12-27T06:56:41.199459-05:
      DOI: 10.1002/app.46142
  • Impact of compression molding conditions on the thermal and mechanical
           properties of polyethylene
    • Authors: Azar Shamloo; Babak Fathi, Saïd Elkoun, Denis Rodrigue, Armand Soldera
      Abstract: Compression molding is a current technique in polymer processing. Despite numerous studies, effect of molding pressure on physical properties has surprisingly not been fully investigated. In this study, the thermal and mechanical behavior of the compression-molded polyethylene were thus explored to better grasp the relationship between processing parameters and ensuing properties. The effect of the molding temperature, pressure, cooling rate, and temperature profile on the tensile and flexural moduli as well as melting point of polyethylene was studied. We conclude that higher tensile and flexural moduli are obtained by increasing pressure and molding temperature, as well as decreasing the cooling rate. Our results were corroborated by X-ray diffraction and differential scanning calorimetry measurements. Moreover, the use of a temperature gradient with different temperatures for the upper and bottom plates of the mold leads to asymmetric samples whose tensile and flexural moduli are improved. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 135, 46176.
      PubDate: 2017-12-27T06:54:52.312983-05:
      DOI: 10.1002/app.46176
  • Nitrogen-rich porous polyaminal network as a platform for iodine
           adsorption through physical and chemical interaction
    • Authors: Yao-Yao Ren; Wuyong Zhang, Yunlong Zhu, De-Gao Wang, Guipeng Yu, Gui-Chao Kuang
      Abstract: A series of nitrogen-rich porous polyaminal networks (PANs) with five different linkages were prepared through a facile route from cost-effective starting materials. Each structural unit bears a different number of phenyl and pyrrolyl rings, which are found to be useful for iodine uptake through a physical adsorption mechanism. The PAN3 bearing the 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BDP) units, which could adsorb iodine by both physical and chemical interaction, achieves an efficient iodine capacity up to 2.81 g/g. Significantly, these new nitrogen-rich PANs might be useful for capture of other volatile compounds. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46106.
      PubDate: 2017-12-27T06:54:35.328143-05:
      DOI: 10.1002/app.46106
  • Corrigendum: Adsorption capability of heavy metals by
           chitosan/poly(ethylene oxide)/activated carbon electrospun nanofibrous
    • Authors: M. I. Shariful; S. Talebian, M. Mehrali, B. C. Ang, M. A. Amal
      PubDate: 2017-12-21T08:11:33.04296-05:0
      DOI: 10.1002/app.46083
  • Optical sensor based on fluorescent PMMA/PFO electrospun nanofibers for
           monitoring volatile organic compounds
    • Authors: Idelma A. A. Terra; Rafaela C. Sanfelice, Gustavo T. Valente, Daniel S. Correa
      Abstract: The development of polymeric materials with superior electrical and/or optical properties is highly demanded for designing optical gas sensors, where conjugated polymers play an important role due to their π-electron conjugation. However, usually the low processability and high cost of these materials hinder technological applications. Here we report on a simple route to develop highly fluorescent electrospun nanofibers of poly(methyl methacrylate) (PMMA) containing low contents of polyfluorene (PFO). The PMMA_PFO nanofibers were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis, while the luminescence properties changes were evaluated by exposing the PMMA_PFO nanofibers to distinct volatile organic compounds (VOCs) including ethanol, toluene, tetrahydrofuran, acetone, dichloromethane, and chloroform. The changes in luminescence properties, specifically fluorescence quenching, of PMMA_PFO nanofibers were analyzed in terms of conformational changes from glassy-phase to β-phase of PFO when the nanofibers were exposed to the VOCs. The developed nanostructured platform showed a suitable response to detect chloroform, with linear responses in the concentration range from 10 to 300 ppm and from 350 to 500 ppm and limits of detection of 47.9 and 15.4 ppm, respectively. The results suggest the PMMA_PFO electrospun nanofibers are highly potential materials for optical gas sensor applications based on luminescence quenching. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46128.
      PubDate: 2017-12-18T04:28:26.945382-05:
      DOI: 10.1002/app.46128
  • The effect of mass transfer resistance and nonuniform initial solvent
           concentration on permeation through polymer membranes
    • Authors: John M. Zielinski; Sacide Alsoy Altinkaya
      Abstract: A numerical simulation model has been developed which enables one to examine the effects of surface mass transfer resistance on the evaluation of permeation (P*), diffusion (D), and solubility (S) coefficients from unsteady-state mass transfer experiments as well as the transmission rate. A complementary analytical expression has been developed which validates the numerical model and facilitates the evaluation of the concentration dependence of P*, D, and S from sequential step-change experiments, under experimental conditions when the surface mass transfer resistance can be neglected. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46126.
      PubDate: 2017-12-18T04:28:21.070934-05:
      DOI: 10.1002/app.46126
  • Research for SEBS/PPA compound-modified asphalt
    • Authors: Feng Zhang; Changbin Hu, Yu Zhang
      Abstract: In this study, polyphosphoric acid (PPA) was used to modify styrene–ethylene/butylene–styrene (SEBS)-modified asphalt further and decrease the SEBS content in asphalt. Different structural analysis methods including morphology observation, infrared spectroscopy, thermal analysis were used to investigate the structural characteristics of asphalt modified by SEBS or PPA before and after short- or long-term thermal ageing. The study shows the suitable addition of PPA can improve the major physical and rheological properties of SEBS-modified (SM) asphalt and the improved properties became more obvious with further ageing. 0.8 wt % PPA can replace 2 wt % SEBS in the modification. Morphology observation showed PPA increased the incompatibility between SEBS and asphalt. Thermal analysis showed PPA changed the energy consumption and mass loss of SM asphalt greatly at elevated temperatures and led to the more complex structural characteristics. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46085.
      PubDate: 2017-12-15T08:41:25.267711-05:
      DOI: 10.1002/app.46085
  • Influence of crosslinking methods toward poly(vinyl alcohol) properties:
           Microwave irradiation and conventional heating
    • Authors: Amit Kumar Sonker; Vivek Verma
      Abstract: In this study, crosslinking of poly(vinyl alcohol) (PVA) with tartaric acid, as crosslinker, is performed using microwave irradiation. A comparison between the properties of PVA crosslinked using microwave irradiation and conventional heating methods is also discussed. While the water absorption, tensile and thermal properties of PVA crosslinked by either of the methods are comparable, microwave irradiation took only one-eighth (14 min) of the time compared to conventional heating. In comparison with PVA (42 MPa), the strength of PVA crosslinked with 35% TA increased to 145 and 153 MPa for conventional heating and microwave irradiation, respectively. Water absorption of crosslinked PVA film is successively reduced to less than 30% in comparison with PVA (∼200%). Moreover, the crosslinked films are stable at higher temperatures in comparison with PVA. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46125.
      PubDate: 2017-12-15T08:41:01.48183-05:0
      DOI: 10.1002/app.46125
  • Analyzing the influence of different synthetic talcs in waterborne
           polyurethane nanocomposites obtainment
    • Authors: Guilherme Dias; Manoela Prado, Christophe Le Roux, Mathilde Poirier, Pierre Micoud, Rosane Ligabue, François Martin, Sandra Einloft
      Abstract: Waterborne polyurethane (WPU) nanocomposites were produced utilizing synthetic talc in gel form in order to improve its physical–chemical properties. Synthetic talc manufactured in nano-gel form are interesting because their interaction with water occurs through hydrogen bonding favoring fillers dispersion within the WPU matrix. WPUs are environmental friendly materials because no organic solvents are used in its production. The nanocomposites obtained with the three synthetic talc nano-gel fillers presented a good dispersion even when higher amounts of fillers were added, as seen by X-ray diffraction, transmission electron microscopy, field emission scanning electron microscopy, and atomic force microscopy analyses. The addition of synthetic talcs improved WPU nanocomposites mechanical properties. Storage and loss modulus results proved fillers incorporation into the WPU matrix corroborating with Fourier transform infrared spectroscopy results. Results demonstrated that synthetic talcs in nano-gel form are interesting to obtain WPU nanocomposites with superior mechanical properties. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46107.
      PubDate: 2017-12-15T08:40:57.202159-05:
      DOI: 10.1002/app.46107
  • Effect of graphene and CNT reinforcement on mechanical and
           thermomechanical behavior of epoxy—A comparative study
    • Authors: Ankita Bisht; Kinshuk Dasgupta, Debrupa Lahiri
      Abstract: Graphene-nanoplateles (Gr) and multiwalled carbon nanotubes (CNTs) reinforced epoxy based composites were fabricated using ultrasonication, a strong tool for effective dispersion of Gr/CNTs in epoxy. The effect of individual addition of two different nanofillers (Gr and CNT) in epoxy matrix, for a range of nanofiller content (0.1–1 wt %), has been investigated in this study. This study compares mechanical and thermomechanical behavior of Gr and CNT reinforced epoxy. Gr reinforcement offers higher improvement in strength, Young's modulus, and hardness than CNT, at ≤0.2 wt %. However, mode-I fracture toughness shows different trend. The maximum improvement in fracture toughness observed for epoxy-Gr composite was 102% (with 0.3 wt % loading of Gr) and the same for epoxy-CNT composite was 152% (with 0.5 wt % loading of CNT). Thorough microstructural studies are performed to evaluate dispersion, strengthening, and toughening mechanisms, active with different nanofillers. The results obtained from all the studies are thoroughly analyzed to comprehend the effect of nanofillers, individually, on the performance of the composites in structural applications. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46101.
      PubDate: 2017-12-14T08:56:38.862332-05:
      DOI: 10.1002/app.46101
  • Ionic liquid mediated surface micropatterning of polymer blends
    • Authors: Elsa Lasseuguette; Jake McClements, Vasileios Koutsos, Thomas Schäfer, Maria-Chiara Ferrari
      Abstract: A polymer of intrinsic porosity (i.e., PIM-1) has been blended with different ionic liquids (ILs) in order to evaluate the effect of the ILs on the microstructure of the polymer blend. [C8MIM][Cl], [BMIM][DCa], [BMPyr][DCa], and [BMIM][Tf2N] have been selected and were mixed with PIM-1. Polymer blends containing up to 80 wt % of ILs were prepared by a casting method with chloroform as solvent. SEM images show that during the film formation a structuring of the surface appears depending on the nature and the concentration of ILs, with appearance of well-defined microstructure in the case of [BMIM][Tf2N] and [BMIM][DCa]. In the case of [BMIM][Tf2N]/PIM-1 film, the lower IL concentration induces the denser film with small micropatterns onto the surface. AFM analysis indicates that the ILs are well dispersed on the surface. X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and water contact angle measurements show that a gradient of IL concentration is observed across the film thickness. It is demonstrated that ILs are versatile co-solvents for inducing controlled micropatterns in polymer membrane surfaces. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46109.
      PubDate: 2017-12-14T08:56:30.612359-05:
      DOI: 10.1002/app.46109
  • Comparing laser diffraction and optical microscopy for characterizing
           superabsorbent polymer particle morphology, size, and swelling capacity
    • Authors: Cole R. Davis; Stacey L. Kelly, Kendra A. Erk
      Abstract: In this study, we determined the accuracy and practicality of using optical microscopy (OM) and laser diffraction (LD) to characterize hydrogel particle morphology, size, and swelling capacity (Q). Inverse-suspension-polymerized polyacrylamide particles were used as a model system. OM and LD showed that the average particle diameter varied with the mixing speed during synthesis for the dry (10–120 μm) and hydrated (34–240 μm) particles. The LD volume and number mean diameters showed that a few large particles were responsible for the majority of the water absorption. Excess water present in the gravimetric swelling measurements led to larger Qs (8.2 ± 0.37 g/g), whereas the volumetric measurements with OM and LD resulted in reduced capacities (6.5 ± 3.8 and 5.7 ± 3.9 g/g, respectively). Results from the individual particle swelling measurements with OM (5.2 ± 0.66 g/g) statistically confirmed that the volumetric methods resulted in a reduced and more accurate measurement of the Q than the gravimetric method. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46055.
      PubDate: 2017-12-14T08:56:20.444299-05:
      DOI: 10.1002/app.46055
  • Improving bonding strength between a hydrophilic coating layer and
           poly(ethylene terephthalate) braid for preparing mechanically stable
           braid-reinforced hollow fiber membranes
    • Authors: Zhuang Zhou; Li-Feng Fang, Sheng-Yao Wang, Hideto Matsuyama
      Abstract: A braid-reinforced hollow fiber membrane with mechanically stable coating layer was prepared by coating a blended polymer dope solution on an alkaline-treated poly(ethylene terephthalate) (PET) braid. The alkaline treatment was carried out to endow the PET braid surface with more polar groups and better hydrophilicity. The results showed that the bonding strength between the hydrophilic coating layer and modified PET braid was about two times as great as that between the coating layer and original PET braid, while the pure water permeability (PWP) of the membrane remained unchanged when the PET braid was simply treated in 3 wt % potassium hydroxide (KOH) solution at 90 °C for 1 h or 1 wt % KOH solution for 6 h. The proposed modification approach proved to be a facile, low-cost, and effective method to improve bonding strength between the coating layer and the braid, while other properties, such as PWP and morphology of the coating layer, of the braid-reinforced hollow fiber membranes were not altered, indicating promising potential in membrane engineering. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46104
      PubDate: 2017-12-14T08:56:13.462667-05:
      DOI: 10.1002/app.46104
  • Assessment of degradation of plasticized poly(vinyl chloride) films
           through polyene formation under isothermal conditions
    • Authors: A. P. Tüzüm Demir; S. Ulutan
      Abstract: The aim of this work is to assess the degradation of flexible poly(vinyl chloride) (PVC) films produced using orthophthalate based and recently introduced nonorthophthlate plasticizers which have compliance with recent environmental regulations. The plasticized PVC films were subjected to several heat treatments at 85–160 °C up to 420 min. Ultraviolet–visible spectroscopy was utilized to follow polyene formation upon dehydrochlorination of PVC. The amount of polyenes formed exhibited difference amongst the films those plasticized with diethyl hexylphthalate, diisodecyl phthalate, dioctyl terephthalate (DOTP), and diisononyl 1,2-cyclohexanedicarboxylic acid (DINCH). The order of polyene concentration formed at the utmost level severe heat treatment is in line with the molecular weight ranking from highest to lowest, as the films with diisodecyl phthalate > DINCH > DOTP > diethyl hexylphthalate. Discoloration assessed in terms of yellowness index revealed that the films having recently introduced plasticizers as DOTP and DINCH were competing well with the films having orthophthalate based plasticizers. Scanning electron microscopy images revealed that the longer times for gelation during their production would improve the maturation of the films although they are already coherent and strong. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46092.
      PubDate: 2017-12-14T08:56:07.331597-05:
      DOI: 10.1002/app.46092
  • Tunability of polycaprolactone hydrophilicity by carboxymethyl cellulose
    • Authors: M. E. Alemán-Domínguez; Z. Ortega, A. N. Benítez, G. Vilariño-Feltrer, J. A. Gómez-Tejedor, A. Vallés-Lluch
      Abstract: Carboxymethyl cellulose (CMC) is herein proposed as additive in polycaprolactone (PCL) matrices to obtain composites with tunable hydrophilicity. This composite material can be obtained by compression molding. The thermogravimetric degradation profile, the FTIR spectra, values of the water contact angle (WCA), water and phosphate-buffered saline uptake values, and the results of a cytotoxicity assessment are presented herein. The concentrations of CMC in the groups of samples are 0, 2, 5, 10, and 20%. The WCA on the prewetted state decreases proportionally to the concentration of the additive. These results evidence the possibility of obtaining a PCL-based composite with tunable hydrophilicity. Besides, the biological assessment does not reveal any cytotoxic effects. Therefore, the addition of CMC entails an innovative strategy to control the water affinity of PCL in biomedical applications where such feature is required to improve diffusion of biological medium through, or accelerate degradation by hydrolysis. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46134.Carboxymethyl cellulose loading can be used as a strategy to increase the hydrophilicity of polycaprolactone matrices. It is possible to tailor the water affinity of the matrix by modifying the content of this additive. Besides, the composites do not show a cytotoxic effect, so they are promising for biomedical applications.
      PubDate: 2017-12-12T07:06:56.432985-05:
      DOI: 10.1002/app.46134
  • Laser confocal microscopical characterization of toughened epoxy resins:
           Correlations between structural features and mechanical properties
    • Authors: Laura Hader-Kregl; Gernot M. Wallner, Reinhold W. Lang, Bernhard Strauß
      Abstract: Laser confocal microscopy is used to analyze the morphology of an epoxy resin (DGEBA) modified with different amounts of toughening agent carboxyl terminated butadiene acrylonitrile (CTBN). The size and phase volume of the distributed spherical toughening particles is ranging from 0.7 to 1.6 µm and 5 to 40 vol %, respectively. These morphological parameters and particles/µm2 reveal a nonlinear relationship with the amount of toughening agent. With increasing particle size and number the glass transition temperature and the tensile modulus are decreasing, whereas the fracture toughness increases. Particles larger than 1.3 µm and a value of particles/µm2 higher than 0.15 exhibit a more significant impact on the resin properties. Linear correlations between the rubber phase volume and the glass transition temperatures as well as the mechanical properties, i.e., tensile modulus and fracture toughness are ascertained. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46094.
      PubDate: 2017-12-12T07:06:37.711021-05:
      DOI: 10.1002/app.46094
  • Water-soluble binder PAALi with terpene resin emulsion as tackifier for
           LiFePO4 cathode
    • Authors: Jiarong He; Haoxiang Zhong, Lingzhi Zhang
      Abstract: Terpene resin (TS) emulsion has been adopted as a tackifier in lithium polyacrylate (PAALi) as water-soluble binder for LiFePO4 (LFP) cathode in Li-ion batteries. TS–PAALi composite binder with optimal ratio of 1:1 (denoted as TS1–PAALi1), shows improved flexibility and enhanced adhesion capability of 0.170 N/cm in comparison with 0.120 N/cm of PAALi after introducing TS as adhesion enhancing agent, which is comparable with that of nonaqueous poly(vinylidene difluoride) (PVDF, 0.171 N/cm) and much better than aqueous sodium carboxymethyl cellulose (CMC, 0.045 N/cm). The electrochemical characteristics of LFP with TS1–PAALi1 have been investigated and further compared with those of PAALi, CMC, and PVDF. LFP with TS1–PAALi1 exhibits superior cycling stability and rate capability, maintaining 65.57% capacity of 0.2 C at 5 C rate in comparison with 60.73%, 57.83%, and 34.79% for PAALi, CMC, and PVDF, respectively. In addition, LFP with TS1–PAALi1 displays excellent cycling performance almost without any capacity fading at 60 °C after 45 cycles at 1 C, much better than that of PAALi, CMC, and PVDF. Cyclic voltammetry and electrochemical impedance spectroscopy reveal that LFP with TS1–PAALi1 has a smaller redox potential difference, lower electrode polarization, and a more favorable electrochemical kinetics (fast lithium diffusion rate) than that of PAALi, CMC, and PVDF, thus more superior electrochemical performances. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46132.
      PubDate: 2017-12-12T07:06:08.145266-05:
      DOI: 10.1002/app.46132
  • Influence of chemical functionalization of carbon nanotubes on their
           dispersibility in alkyl methacrylate polymer matrix
    • Authors: Fabio Faraguna; Elvira Vidović, Ante Jukić
      Abstract: Nanocomposites based on poly(methyl methacrylate) (PMMA) and poly(methyl methacrylate-co-octadecyl methacrylate) (M/O) matrices and four different types of multiwall carbon nanotubes: pristine, oxidized (MWCNT–COOH), methyl ester (MWCNT–COOCH3), and dodecyl ester (MWCNT–COOC12H25) functionalized, were prepared in situ by radical (co)polymerization. The effectiveness of preparation of nanocomposites regarding dispersion and distribution of various MWCNT in polymer matrices was sized by Scanning electron microscopy. In case of PMMA matrix, the best dispersion and distribution were accomplished for MWCNT–COOCH3 due to their chemical resemblance with polymer matrix. After the introduction of 10 mol % of octadecyl methacrylate in polymer matrix a fairly good dispersion and distribution of MWCNT–COOCH3 were retained. The addition of 1 wt % of MWCNTs caused a significant reduction in the degree of polymerization of the PMMA matrix. But at the same time, the present MWCNTs increased storage modulus of PMMA nanocomposites except for dodecyl ester functionalized MWCNT. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46113.
      PubDate: 2017-12-11T08:01:30.076639-05:
      DOI: 10.1002/app.46113
  • Mechanical performance of tubular composites reinforced by innovative 3D
           integrated knitted spacer fabrics
    • Authors: Elahe Omrani; Hossein Hasani, Faraneh Esmaeili
      Abstract: This article aimed to investigate the mechanical performance of 3D integrated knitted spacer composites with a tubular shape, in term of internal hydrostatic and external static pressures (ESP). All the tubular-knitted fabrics were produced on a modern flat knitting machine using untwisted glass and HT-nylon yarns. Then, the epoxy resin was transferred through the whole fabric structure via vacuum infusion molding process. Produced tubular composites were subjected to internal hydrostatic and ESP. Accordingly, force–displacement curves were obtained and experimental results were discussed. The results revealed that the tubular composite samples containing non-knitting yarns show 27.33 and 37.50% improvement in internal hydrostatic and ESP, respectively, compared with the plain knitted fabric reinforced composite. Also, the finding demonstrated that mechanical performance of the tubular-knitted spacer composites is highly affected by aspect ratio and the number of connecting layers. Knitted spacer reinforced composite containing 5 and 10 connecting layers can improve the resistance against internal hydrostatic pressure 35.08 and 51.29%, respectively, compared with the plain knitted reinforced composites. In this case, 84.20 and 89.86% improvement can be achieved in term of the resistance against ESP. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46074.
      PubDate: 2017-12-11T08:01:21.464825-05:
      DOI: 10.1002/app.46074
  • Effect of titanium dioxide on the UV-C ageing behavior of silicone rubber
    • Authors: Hui Zhang; Hao Yang, Baoqing Shentu, Songjun Chen, Ming Chen
      Abstract: The ultraviolet (UV)-C ageing behavior of silicone rubber (SiR) incorporated with titanium dioxide nanoparticles (nano-TiO2) was studied under UV-C radiation. The SiR incorporated with nano-TiO2 displayed excellent physical properties when exposed to UV-C radiation. With the increase of the ageing time, the SiR with nano-TiO2 showed no significant change in crosslinking density and Shore A hardness. Moreover, compared with the SiR without nano-TiO2, the SiR incorporated with nano-TiO2 also exhibited high retention ratio in tensile properties, especially elongation at break. It was found that nano-TiO2 was a good ultraviolet light stabilizer during the UV ageing process of SiR and the optimum content of nano-TiO2 was 2 phr. The results of Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy showed the appearance of OH and CO and the decrease of the intensity of SiC2O2 in SiR samples during the process of UV-C ageing. Based on these results, a possible UV ageing mechanism of SiR could be proposed. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46099.
      PubDate: 2017-12-11T08:01:18.240132-05:
      DOI: 10.1002/app.46099
  • Reinforcement of the mechanical properties in nitrile rubber by adding
           graphene oxide/silicon dioxide hybrid nanoparticles
    • Authors: Zhao Zhang; Xianru He, Xin Wang, Alisson M. Rodrigues, Rui Zhang
      Abstract: Graphene oxide (GO) and silicon dioxide (SiO2) nanoparticles have been hybridized for improving the mechanical and dynamic mechanical properties of nitrile rubber (NBR). SiO2 nanoparticles were homogeneously dispersed on the surface and between layers of GO, and the new hybrid nanoparticles formed (GO/SiO2) had better thermal stability than GO. To evaluate the mechanical properties, GO/SiO2/NBR nanocomposites were prepared by solution blending and mechanical solution methods. It was observed that tensile strength increased in a larger grade in GO/SiO2/NBR nanocomposites than that in GO/NBR and SiO2/NBR nanocomposites, while the elongation at break only changes smoothly. Moreover, dynamics measurements also indicated that the elasticity increased after adding GO/SiO2 hybrid nanoparticles in NBR. From morphology's analysis of GO/SiO2/NBR and GO/NBR nanocomposites, it is was conclude that the hybridization of the GO/SiO2 was the determining factor for the reinforcement of the mechanical properties and elasticity of the NBR. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46091.
      PubDate: 2017-12-11T00:51:06.818088-05:
      DOI: 10.1002/app.46091
  • Aliphatic SPI charge-transfer complex hybrid films for high temperature
           polymer electrolyte membrane fuel cells
    • Authors: Liana Christiani; Kazunari Sasaki, Masamichi Nishihara
      Abstract: A new method to synthesize polymer electrolyte membranes based on charge-transfer (CT) complexes for high temperature fuel cells is investigated. Aliphatic sulfonated polyimide (SPI) CT complex hybrid films are prepared. Aliphatic units are introduced into the SPI main chain to increase the elasticity compared with aromatic SPI films. Electron-donating compounds are included to form a CT complex, resulting in improved control over mechanical strength, water uptake, and thermal stability. The resulting thermal properties of the SPI CT films are sufficient to operate at elevated temperature (up to 120 °C), and the proton conductivity is comparable to that of Nafion 115. These films are thus promising alternative membranes for high temperature polymer electrolyte fuel cell applications. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46087.
      PubDate: 2017-12-11T00:50:59.584449-05:
      DOI: 10.1002/app.46087
  • Stability and spinnability of modified melamine–formaldehyde resin
           solution for centrifugal spinning
    • Authors: Chengdong Xiong; Xianglong Li, Teng Hou, Bin Yang
      Abstract: Melamine microfibers were first prepared by centrifugal spinning. The stability and spinnability of a melamine–formaldehyde (MF) resin solution were improved as expected by adding various modifier combinations. Considering the storage stability of solutions characterized by visual inspection, turbidity tests, and viscosity measurements and combined with the fiber morphology, the optimal modifier combination was obtained. The spun fibers manifested a good morphology and thermal stability as measured by scanning electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. Moreover, microfibers prepared by three spinning methods (centrifugal spinning, electrospinning, and centrifugal electrostatic spinning) were compared to choose the suitable spinning method for different fields in the future. This work provides systematic and scientific guidance on the synthesis of MF resin solutions and rapid mass production of melamine microfibers and also demonstrates that centrifugal spinning of melamine microfiber is a promising candidate for flame retardance and CO2 adsorption at elevated temperature. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46072.
      PubDate: 2017-12-08T08:02:57.377163-05:
      DOI: 10.1002/app.46072
  • Properties of polythiourethanes prepared by thiol–isocyanate click
    • Authors: Junghwan Shin; Joonmo Lee, Han Mo Jeong
      Abstract: Polythiourethane networks with systematic compositional variations of thiol [ethoxylated trimethylol-propane tri(3-mercapto-propionate), ETTMP1300 and pentaerythritol tetra(3-mercapto-propionate), PETMP] and isophorone diisocyanate (IPDI), i.e., IPDI/ETTMP1300/PETMP = 100/100/0, 100/80/20, 100/60/40, 100/40/60, 100/20/80, and 100/0/100, were prepared by base catalyzed thiol–isocyanate click type reaction where the base catalyst (tributylamine, TBA) was photolytically generated using photolatent amine (TBA·tetraphenylborate salt, TBA·HBPh4). The kinetics of the polythiourethane network formation investigated using real-time infrared indicates that the thiol–isocyanate coupling reaction was successfully triggered photolytically and the conversion of both thiol and isocyanate reached near 100% in a matter of minutes. The Tg of the polythiourethane networks progressively increases (–8 to 143 °C by DMTA) as a function of the PETMP content due to the higher extent of crosslinks, also resulting in enhanced rubbery modulus. Very narrow full width at half maximum (15–28 °C) of tan δ peak was obtained for all six sets of polythiourethane networks, which is induced by the highly uniform and dense structures of thiol-based polymeric network. Energy damping performance of polythiourethane networks measured by nondestructive impact testing exhibited remarkably high (∼95%) and the relationship with temperature was in accordance with tan δ peak. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46070.
      PubDate: 2017-12-08T08:02:41.31877-05:0
      DOI: 10.1002/app.46070
  • A novel thermosensitive triblock copolymer from 100% renewably sourced
           poly(trimethylene ether) glycol
    • Authors: Cong Zhang; Huacheng Luan, Guiyou Wang
      Abstract: Bio-based amphiphilic triblock copolymers with 100% renewably sourced poly(trimethylene ether) glycol (PO3G) as the hydrophobic blocks and statistical copolymer of 2-(2-methoxyethoxy)ethyl methacrylate (MEO2MA) and oligo(ethylene glycol)methacrylate (OEGMA) [P(MEO2MA-stat-OEGMA)] as the hydrophilic blocks are synthesized and characterized. It is found that the molar ratio of MEO2MA/OEGMA among the resulting copolymers is approximately 70/30. The degree of polymerization (DP) of P(MEO2MA-stat-OEGMA) block ranges from 16 to 90, and the DP of PO3G block is fixed at 35. The amphiphilic copolymers could form core-shell micelles self-assembly in aqueous solution at low concentrations, and the micelles are in spherical shape with sizes varying from 121 to 188 nm. With the increasing length of hydrophilic blocks, the critical micelle concentration increases from 2.15 to 13.8 mg L−1, and the lower critical solution temperature improves from 32.5 to 38.4 °C. The in vitro doxorubicin (DOX) release study shows that all DOX-loaded micelles have a higher release rate at 37 °C than that at 25 °C. Cytotoxicity test reveals that the blank micelles are nearly nontoxic. These results indicate that the block copolymer micelles containing 100% renewably sourced PO3G can serve as a potential drug delivery carrier. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46112.
      PubDate: 2017-12-08T08:02:22.721849-05:
      DOI: 10.1002/app.46112
  • Simultaneous decision analysis on the structural and mechanical properties
           of polymeric microcellular nanocomposites foamed using CO2
    • Authors: Mahsa Daryadel; Taher Azdast, Rezgar Hasanzadeh, Siamak Molani
      Abstract: In this study, the effects of nano Fe2O3 content and foaming temperature and time are investigated on the various structural and mechanical properties of polypropylene in a batch foaming process with CO2 using Taguchi approach. Cell size, relative density, and specific impact strength and hardness are considered as different criteria. The results indicated that the cell sizes are below 10 μm and a 20% improvement is observed in the microcellular nanocomposite samples containing 4 wt % nano Fe2O3. A 20% improvement is observed in specific impact strength by increasing 4 wt % of nano Fe2O3. Also, a simultaneous decision analysis is performed and the best sample with respect to considered structural and mechanical properties is selected using multi-criteria decision making methods. The results demonstrated that the microcellular nanocomposite foams containing 4 wt % of nano Fe2O3 are the best samples. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46098.
      PubDate: 2017-12-08T08:01:58.994379-05:
      DOI: 10.1002/app.46098
  • Monomer atomic configuration as key feature in governing the gas transport
           behaviors of polyimide membrane
    • Authors: P. C. Tan; B. S. Ooi, A. L. Ahmad, S. C. Low
      Abstract: Although the molecular design of polyimide has been extensively investigated, the role of monomer's atomic configuration in controlling the structure of polyimide membrane hence its gas transport behaviors remains relatively uncertain. Therefore, a series of polyimides with different monomer combinations were synthesized to determine the crucial features of monomer that can impose great influence on membrane properties such as the fractional free volume (FFV). The results showed that the polyimide chain length (Mw) depended strongly on the monomer reactivity, which was primarily controlled by the steric hindrance of monomers' substituent instead of their electronic nature. In addition, the polarity and atomic configuration of monomer were found to be the two dominant factors in governing the membrane FFV. A polyimide model was also constructed and validated by molecular dynamics simulation to predict the gas transport behaviors (solubility and diffusivity) of copolyimide membranes. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46073.
      PubDate: 2017-12-07T07:21:20.717842-05:
      DOI: 10.1002/app.46073
  • Thermal and UV degradation of polypropylene with pro-oxidant. Abiotic
    • Authors: Francisco J. Arráez; María Luisa Arnal, Alejandro J. Müller
      Abstract: The oxodegradation of an injection molding grade polypropylene (PP), formulated with 0%, 1.5%, and 3% w/w of a pro-oxidant additive, was studied. The degradation was conducted in a weathering tester at 60 °C for 40 h. The process was monitored by Fourier transform infrared spectroscopy, standard differential scanning calorimetry, and successive self-nucleation and annealing. Neat PP samples did not exhibit significant changes during the exposure time employed. PP samples with oxo-additive presented similar changes independently of the amount of oxo-degradative additive employed; however, the changes manifested more rapidly in the formulation with higher pro-oxidant content. Fourier transform infrared spectroscopy studies revealed the presence of hydroxyl and carbonyl functional groups whereas differential scanning calorimetry tests showed the decrease in the melting and crystallization temperatures as a consequence of the chain scission and oxidation reactions taking place during exposure. In addition, the induction time (tid) of the oxo-degradative process was determined for each technique employed and successive self-nucleation and annealing was found to be the most sensitive characterization technique to reveal structural modifications in PP samples. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46088.
      PubDate: 2017-12-07T07:20:37.989281-05:
      DOI: 10.1002/app.46088
  • Enhanced oil recovery from high-salinity reservoirs by cationic gemini
    • Authors: Tingjiao Yuan; Zhe Liu, Ruimin Gao, Guangfa Hu, Gai Zhang, Jianshe Zhao
      Abstract: In order to enhance oil recovery from high-salinity reservoirs, a series of cationic gemini surfactants with different hydrophobic tails were synthesized. The surfactants were characterized by elemental analysis, infrared spectroscopy, mass spectrometry, and 1H-NMR. According to the requirements of surfactants used in enhanced oil recovery technology, physicochemical properties including surface tension, critical micelle concentration (CMC), contact angle, oil/water interfacial tension, and compatibility with formation water were fully studied. All cationic gemini surfactants have significant impact on the wettability of the oil-wet surface, and the contact angle decreased remarkably from 98° to 33° after adding the gemini surfactant BA-14. Under the condition of solution salinity of 65,430 mg/L, the cationic gemini surfactant BA-14 reduces the interfacial tension to 10−3 mN/m. Other related tests, including salt tolerance, adsorption, and flooding experiments, have been done. The concentration of 0.1% BA-14 remains transparent with 120 g/L salinity at 50 °C. The adsorption capacity of BA-14 is 6.3–11.5 mg/g. The gemini surfactant BA-14 can improve the oil displacement efficiency by 11.09%. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46086.
      PubDate: 2017-12-07T07:18:40.07485-05:0
      DOI: 10.1002/app.46086
  • The enhancement performances of cotton stalk fiber/PVC composites by
           sequential two steps modification
    • Authors: Ya-Yu Li; Bin Wang, Bo Wang, Ming-Guo Ma
      Abstract: In the present study, the cotton stalk fiber (CSF) was modified by sequential two steps of alkali and copper ethanolamine (CE) solution treatment. The unmodified and modified CSF/poly(vinyl chloride) (CSF/PVC) composites were prepared. The mechanical and physical performances of the various CSF/PVC composites were studied comparatively. By the modification of CE solution, all the tensile strength, tensile modulus, impact strength, water resistance, and heat distortion temperature of samples were enhanced continuously. The sample with comprehensive properties was obtained using 2% concentration of CE. The composites were also prepared with different CSF content. By increasing the CSF loading, all the tensile strength, elongation at breakage, tensile modulus, and heat distortion temperature of samples were enhanced. The existence of copper on the surface of CSF improved the thermal stability of the CSF/PVC composites. Water retention value, oil retention value, and scanning electron microscope were applied to reveal the components and microscopic change of the composites. The possible reaction mechanism of modification was proposed based on the experimental results and according to the previous literature. This method reported here may provide a new way for the fabrication of CSF/PVC composite in engineering applications. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46090.
      PubDate: 2017-12-06T05:55:32.019204-05:
      DOI: 10.1002/app.46090
  • Effect of POSS-grafted titanium dioxide on the electrical and thermal
           properties of LDPE/TiO2 polymer nanocomposite
    • Authors: Tung Tran Anh; Michel Fréchette, Éric David, René Veillette, Patricia Moraille
      Abstract: Two types of nanocomposites have been fabricated by a ball-milling technique. The first type consists of untreated titanium dioxide (TiO2) incorporated into low-density polyethylene (LDPE). For the second one, TiO2 filler chemically treated with trisilanol phenyl–polyhedral oligomeric silsesquioxane (TP–POSS) as compatibilizing agent was ball-milled with LDPE. All specimens were tested by microstructure analysis and thermal, dielectric characterization techniques. Microstructure analysis by atomic force microscopy and scanning electron microscopy show clearly an increased dispersion in presence of POSS. Scanning electron microscopy even shows the formation of a particular structure due possibly to interactions between functionalization. It was observed that the modification of the surface of TiO2 by the POSS decreased the dielectric loss. All nanocomposites containing treated TiO2 revealed an improvement in thermal conductivity, with the most distinct value of 19% in case of LDPE containing 5 wt % treated TiO2. The incorporation of TiO2 fillers seems to reduce the dielectric breakdown strength of the nanocomposites. However, nanocomposites containing 3 and 5 wt % treated TiO2 have exhibited a slightly enhancement in dielectric breakdown strength up to 5%. The improvement in surface resistance to partial discharge was found in all nanocomposites specimens, especially for both types of composite containing 7 wt % untreated and treated TiO2. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 135, 46095.
      PubDate: 2017-12-05T04:40:37.905671-05:
      DOI: 10.1002/app.46095
  • Research of phenolic crosslinker gel for profile control and oil
           displacement in high temperature and high salinity reservoirs
    • Authors: Jichao Fang; Jianhai Wang, Quanyi Wen, Sisi Fang, Xiaoqing He, Yan Ma, Yining Wu, Caili Dai
      Abstract: To further enhance oil recovery of high temperature and high salinity reservoir at Tahe Oilfield, field test results from profile control and oil displacement of gel were carried out in this article. Static and dynamic evaluations were performed through gel strength code method, environment scanning electron microscope, and physical simulation experiment devices. The field test results show that, under the conditions of high temperature (100.8 °C) and salinity (19.8 × 104 mg/L), the stable gel system was formed with gelling time range from 26 to 45 h, gel strength ranging from E to H, and dehydrating amount lower than 3.0% after ageing 60 days. Meanwhile, the microstructure is very stable. When the permeability and gel strength ranges from 0.212 to 0.970 μm2 and E to H, respectively, the plugging ratio is larger than 85%, and the plugging performance becomes better with the increase of permeability or gel strength. Due to the profile improvement rate of 99.8% and the oil recovery up to 28.5%, profile control and oil displacement technology of gel can effectively promote fluid diverting. The water cut reduced from 95.2% to 89.0% during field test carried out in Tahe Oilfield, which means that profile control and oil displacement technology of gel could stabilize oil production by water control effectively. Also, this technology has a wide application prospective that provides with strong technical support for further enhanced oil recovery in high temperature and high salinity reservoirs. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 135, 46075.
      PubDate: 2017-12-05T04:40:31.158827-05:
      DOI: 10.1002/app.46075
  • Comparative mucoadhesive study of hyaluronic acid-based conjugates on
           different mucosae
    • Authors: Flavia Laffleur
      Abstract: The incentive of this study was to provide a detailed mucoadhesive comparison on adhesive properties on diverse mucosal surfaces such as nasal, buccal, and vaginal mucosa, respectively. Mucoadhesive hyaluronic acid–cysteine ethyl ester (HA–SH) conjugate was synthesized by the anchorage of sulfhydryl groups (SH) on the polymeric backbone of HA via amide bond formation between the carboxylic acid moieties of hyaluronic acid and sulfhydryl groups of cysteine ethyl ester. Histology assay in terms of alcian blue staining was performed on mucosal tissue in order to evaluate the potential impact on viability. The proficiency of water uptake was studied in various simulated body fluid. Moreover, mucoadhesive assays based on rotating cylinder, total work of adhesion, and maximum detachment force were carried out on various mucosae. The findings revealed in presence of 2.7-, 2.6-, and 1.25-fold improvement in swelling behavior in comparison to unmodified HA on nasal, buccal, and vaginal mucosa. Furthermore, mucoadhesive studies showed a 3.2-, 2.6-, 2.6-fold more extended residence time on nasal, buccal, and vaginal in presence of HA–SH in comparison to unmodified HA, respectively. Taken together, the comprehensive mucoadhesive study serve as guidance in the development of mucoadhesive drug delivery systems for versatile application. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46071.
      PubDate: 2017-12-05T04:40:27.287813-05:
      DOI: 10.1002/app.46071
  • Layer-by-layer fabrication of nacre inspired epoxy/MMT multilayered
    • Authors: Sadia Batool; Rohama Gill, Muhammad Arshad, Humaira Masood Siddiqi, Shahid Saeed Qureshi
      Abstract: The organic–inorganic hybrid multilayered composites are prepared using a unique combination of poly[(o-cresyl glycidyl ether)-co-formaldehyde] (CNER), amino modified montmorillonite (NH2-MMT), and polyethyleneimine (PEI). This tricomponent composite multilayer PEI(CNER/NH2-MMT/PEI)n deposited via layer-by-layer technique is based upon synergistic combination of covalent and hydrogen bonding. The growth of multilayer was monitored using UV–vis spectroscopy and ellipsometry. When subjected to optical analyses, the prepared multilayered composite films revealed profound optical transmittance ∼83%–87%. The surface morphological analysis by atomic force microscopy and scanning electron microscopy revealed uniform arrangement of organic–inorganic components with relative increase in intensity of elements (C, N, O, Si) as confirmed by X-ray photoelectron spectroscopy studies. The multilayered composites possess 1.99 GPa hardness making them potential candidate for a number of applications where mechanical strength is desired. Moreover, significant resistance against alkaline and organic solvents at minimal deterioration of circa 0.12% has also been observed for the prepared films. The epoxy clay based thin films being robust, scratch resistant, hydrophilic, chemically inert, and mechanically strong are potential candidates for advanced environmental applications. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46079.
      PubDate: 2017-12-03T10:57:05.880846-05:
      DOI: 10.1002/app.46079
  • A new thermoset for separation of polystyrene and naphthalene in
           preparative chromatography
    • Authors: Wesley de Oliveira Rosa; Vagner R. Botaro
      Abstract: Many research groups in recent years have demonstrated the importance of obtaining new materials and reducing environmental impact. In this context, the chemical modification of cellulose and its derivatives has received much attention. This study synthesized cellulose acetate gel (CAMDIH) obtained through the modification of cellulose acetate (CA) with a degree of substitution of 2.5, by crosslinking reactions using 4,4′-diphenylmethane diisocyanate in homogeneous medium. The formation of crosslinks were observed by the presence of Fourier transform infrared spectroscopy absorption bands at 3046 and 864 cm−1, which correspond to the absorption of aromatic groups associated with the incorporation of 4,4′-diphenylmethane diisocyanate in the CA structure. The potential applications of the gel as a stationary phase were tested using column chromatography in the fractionation and separation of standard solutions of polystyrene and naphthalene. The findings showed the effectiveness of the gel as a stationary state in the separation of mixture compounds. Furthermore, the study found that CAMDHI is an innovative material when considering its simple synthesis and the low costs involved in the process. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 135, 46063.
      PubDate: 2017-12-03T10:55:30.001125-05:
      DOI: 10.1002/app.46063
  • Fully bio-based polyesters derived from 2,5-furandicarboxylic acid
           (2,5-FDCA) and dodecanedioic acid (DDCA): From semicrystalline
           thermoplastic to amorphous elastomer
    • Authors: Zhen Jia; Jinggang Wang, Liyuan Sun, Jin Zhu, Xiaoqing Liu
      Abstract: A serials of fully bio-based poly(ethylene dodecanedioate-2,5-furandicarboxylate) (PEDF) were synthesized from Dodecanedioic acid (DDCA), 2,5-Furandicarboxylic acid (2,5-FDCA), and ethylene glycol through a two-step procedure consisted of transesterification and polycondensation. After their chemical structures were confirmed by Nuclear Magnetic Resonance and Fourier Transform Infrared Spectroscopy, their thermal, mechanical, and biodegradation properties were investigated in detail. Results showed that the chemical composition of PEDFs could be easily controlled by the feeding mole ratio of DDCA to FDCA and they possessed the characteristic of random copolyester with the intrinsic viscosity ranged from 0.82 to 1.2 dL/g. With the varied mole ratio of DDCA to FDCA, PEDFs could be changed from semicrystalline thermoplastic to the completely amorphous elastomer, indicated by the elongation at break ranged from 4 for poly(ethylene 2,5-furandicarboxylate) to 1500% for amorphous PEDF-40. The amorphous PEDF-30 and PEDF-40 showed satisfactory shape recovery after cyclic tensile test, which was the typical behavior for elastomer. Enzymatic degradation test indicated that all the PEDFs were biodegradable and the degradation rate was heavily affected by their chemical compositions. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 135, 46076.
      PubDate: 2017-11-29T08:46:13.028585-05:
      DOI: 10.1002/app.46076
  • Biodegradable polymeric injectable implants for long-term delivery of
           contraceptive drugs
    • Authors: Ohan S. Manoukian; Michael R. Arul, Naseem Sardashti, Teagan Stedman, Roshan James, Swetha Rudraiah, Sangamesh G. Kumbar
      Abstract: Development of injectable, long-lasting, contraceptive drug delivery formulations, and implants are highly desired to avoid unplanned pregnancies while improving patient compliance and reducing adverse side effects and treatment costs. The present study reports on the fabrication and characterization of two levonorgestrel (LNG) microsphere injectable formulations. Poly(ɛ-caprolactone) (PCL) with 12.5% and 24% (w/w) LNG were fabricated into microspheres, measuring 300 ± 125 µm, via the oil-in-water (o/w) emulsion solvent evaporation technique. Formulations showed sustained drug release up to 120 days. FTIR, XRD, DSC, and TGA confirmed the absence of LNG chemical interaction with PCL as well as its molecular level distribution. The in vitro release of LNG was calculated to be Fickian diffusion controlled and properly characterized. The inclusion of multiple elevated release temperatures allowed for the application of the Arrhenius model to calculate drug release constants and representative sampling intervals, demonstrating the use of elevated temperatures for accelerated-time drug release studies. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46068.
      PubDate: 2017-11-29T02:30:57.922868-05:
      DOI: 10.1002/app.46068
  • Polymersome formation mechanism and formation rate in stirred-tank
    • Authors: Sarah T. Poschenrieder; Marianne Hanzlik, Kathrin Castiglione
      Abstract: Uniform polymersomes (polymer vesicles) made of poly(2-methyloxazoline)15-b-poly(dimethylsiloxane)68-b-poly(2-methyloxazoline)15 (PMOXA15–PDMS68–PMOXA15) can be formed in miniaturized-stirred tank reactors by the aid of a recently published process. In this study, the occurring self-assembly mechanism was elucidated by using transmission electron microscopy. Subsequent to the initial formation of small spherical micelles and the following fusion to worm-like micelles, two simultaneously occurring pathways, describing the transformation of further intermediate structures to the desired vesicles, were found. The resulting particle increase was followed by dynamic light scattering. Thus, the vesicle formation rate was judged by the linear increase of the particle diameter over time. While temperature showed no influence, higher initial polymer concentrations and lower final solvent concentrations accelerated the polymersome formation. Besides, the process was crucially dependent on the agitation speed. While spherical micelles did not transform into polymersomes when no stirring or too slow stirring is applied, the self-assembly process was accelerated by increasing the agitation speed. Uniform polymeric vesicles can be formed under vigorous stirring in stirred-tank reactors in short process times. In this study, the underlying mechanisms of vesicle formation were elucidated, showing that the polymer forms small micellar structures before undergoing two separate pathways to form the desired vesicular structures. The formation rate of the polymer vesicles was mainly dependent on the agitation speed but also on the polymer and solvent concentrations, highlighting the need for controlled formation conditions. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 135, 46077.
      PubDate: 2017-11-29T02:30:46.268334-05:
      DOI: 10.1002/app.46077
  • Synthesis of reusable silicone foam containing carbon nanotubes for oil
           spill remediation
    • Authors: Elpida Piperopoulos; Luigi Calabrese, Emanuela Mastronardo, Edoardo Proverbio, Candida Milone
      Abstract: The aim of this work is the synthesis of silicone foam containing carbon nanotubes (CNT) for oil spills remediation. The CNT silicone foams are obtained by foaming a solution of a silicone matrix with CNT filler (5.6 wt %) in presence of a Sn-based catalyst. Pristine and functionalized CNT have been used. All the obtained materials present a foam morphology with an open cell structure. Each foam is tested in four commonly used oils (kerosene, pump oil, naphtha, and crude oil). Among all, the foam filled with pristine CNT shows the highest sorption capacity (800 wt % in virgin naphtha) and an excellent reusability (up to 10 times). © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 135, 46067.
      PubDate: 2017-11-28T07:06:58.135214-05:
      DOI: 10.1002/app.46067
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