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INORGANIC CHEMISTRY (45 journals)

Showing 1 - 34 of 34 Journals sorted alphabetically
Acta Polymerica     Hybrid Journal   (Followers: 9)
Additives for Polymers     Full-text available via subscription   (Followers: 20)
Advances in Inorganic Chemistry     Full-text available via subscription   (Followers: 9)
Advances in Polymer Technology     Open Access   (Followers: 13)
Bioinorganic Chemistry and Applications     Open Access   (Followers: 5)
Comments on Inorganic Chemistry: A Journal of Critical Discussion of the Current Literature     Hybrid Journal   (Followers: 1)
Communication in Inorganic Synthesis     Open Access  
European Journal of Inorganic Chemistry     Hybrid Journal   (Followers: 10)
European Polymer Journal     Hybrid Journal   (Followers: 44)
High Performance Polymers     Hybrid Journal   (Followers: 1)
Indian Journal of Chemistry - Section A     Open Access   (Followers: 9)
Inorganic and Nano-Metal Chemistry     Hybrid Journal  
Inorganic Chemistry     Hybrid Journal   (Followers: 31)
Inorganic Chemistry Communications     Hybrid Journal   (Followers: 13)
Inorganic Chemistry Frontiers     Hybrid Journal   (Followers: 4)
Inorganic Materials     Hybrid Journal   (Followers: 5)
Inorganic Materials: Applied Research     Hybrid Journal   (Followers: 1)
Inorganica Chimica Acta     Hybrid Journal   (Followers: 6)
International Journal of Bio-Inorganic Hybrid Nanomaterials     Open Access   (Followers: 2)
International Journal of Inorganic Chemistry     Open Access   (Followers: 3)
JBIC Journal of Biological Inorganic Chemistry     Hybrid Journal   (Followers: 2)
Journal of Inorganic and Organometallic Polymers and Materials     Hybrid Journal   (Followers: 8)
Journal of Inorganic Biochemistry     Hybrid Journal   (Followers: 4)
Journal of Inorganic Chemistry     Open Access   (Followers: 3)
Journal of Polymers and the Environment     Hybrid Journal   (Followers: 1)
Journal of Progressive Research in Chemistry     Open Access  
Journal of Separation Science     Hybrid Journal   (Followers: 10)
Materials Today Chemistry     Hybrid Journal   (Followers: 2)
Open Journal of Inorganic Chemistry     Open Access   (Followers: 1)
Polymer Bulletin     Hybrid Journal   (Followers: 7)
Polymer Composites     Hybrid Journal   (Followers: 18)
Russian Journal of Inorganic Chemistry     Hybrid Journal  
Separation Science plus (SSC plus)     Hybrid Journal  
Zeitschrift für anorganische und allgemeine Chemie     Hybrid Journal   (Followers: 1)
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High Performance Polymers
Journal Prestige (SJR): 0.332
Citation Impact (citeScore): 1
Number of Followers: 1  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 0954-0083 - ISSN (Online) 1361-6412
Published by Sage Publications Homepage  [1169 journals]
  • Electromagnetic interference shielding effectiveness of polypyrrole-silver
           nanocomposite films on silane-modified flexible sheet

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      Authors: Karim Benzaoui, Achour Ales, Ahmed Mekki, Abdelhalim Zaoui, Boudjemaa Bouaouina, Ajay Singh, Oussama Mehelli, Mehdi Derradji
      Abstract: High Performance Polymers, Ahead of Print.
      The conventional electromagnetic interference (EMI) shielding materials are being gradually replaced by a new generation of supported conducting polymer composites (CPC) films due to their many advantages. This work presents a contribution on the effects of silane surface–modified flexible polypyrrole-silver nanocomposite films on the electromagnetic interference shielding effectiveness (EMI-SE). Thus, the UV-polymerization was used to in-situ deposit the PPy-Ag on the biaxial oriented polyethylene terephthalate (BOPET) flexible substrates whose surfaces were treated by 3-aminopropyltrimethoxysilane (APTMS). X-ray Photoelectron Spectroscopy (XPS) analyzes confirmed the APTMS grafting procedure. Structural, morphological, thermal, and electrical characteristics of the prepared films were correlated to the effect of substrate surface treatment. Thereafter, EMI-SE measurements of the elaborated films were carried out as per ASTM D4935 standard for a wide frequency band extending from 50 MHz to 18 GHz. The obtained results confirmed that the APTMS-treated BOPET film exhibit higher EMI shielding performance and better electrical characteristics compared to the untreated film. In fact, a 32% enhancement of EMI-SE was noted for the treated films compared to the untreated ones. Overall, these results put forward the role played by the surface treatment in strengthening the position of flexible PPy-Ag supported films as high-performance materials in electronic devices and electromagnetic interference shielding applications.
      Citation: High Performance Polymers
      PubDate: 2021-12-28T02:11:08Z
      DOI: 10.1177/09540083211064535
       
  • Improved interfacial performance of carbon fiber/polyetherimide composites
           by polyetherimide and modified graphene oxide complex emulsion type sizing
           agent

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      Authors: Fan Chen, Xiaofang Liu, Hansong Liu, Shuang Li, Shile Li, Tianpei Sun, Yan Zhao, Kai Wang
      Abstract: High Performance Polymers, Ahead of Print.
      In the field of interfacial enhancement of composite, sizing method has attracted extensive attention. In this research, a new complex emulsion type sizing agent containing polyetherimide (PEI) and covalently chemical functionalized graphene oxide (GO) was first proposed to further improve the interfacial adhesion of carbon fiber (CF)/PEI composites, adapt to the high processing temperature, and overcome the shortcomings of the solution type sizing agent. The emulsion was prepared by the emulsion/solvent evaporation method. In order to avoid the agglomeration of nanomaterials on CF surface, the monomer and polymer structure of PEI was used to functionalize GO, so as to achieve better compatibility and dispersion of GO in PEI. The physicochemical state of CF surface was characterized and the successful introduction of GO was verified. The microbond test revealed that the introduction of GO further improved the IFSS compared with only PEI sizing. When GO grafted with PEI was used as the main component of the sizing agent, the IFSS reached the largest with an increasement of 55.96%. The mechanism of interfacial reinforcement was proposed. Increased ability of mechanical interlocking, the mutual solubility between PEI molecular chains, and the improvement in wettability may be beneficial to the interfacial strength. This mild and effective modification method provided theoretical guidance for the interfacial enhancement of composites and was expected to be applied in industrial production.
      Citation: High Performance Polymers
      PubDate: 2021-12-22T10:00:41Z
      DOI: 10.1177/09540083211053742
       
  • Effect of highly thermally conductive Ag@BN on the thermal and mechanical
           properties of phthalonitrile resins

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      Authors: Xinggang Chen, Xiongwei Qu, Jun Chen, De Zheng
      Abstract: High Performance Polymers, Ahead of Print.
      Ag@BN/phthalonitrile resin composites were prepared using highly thermally conductive BN modified by Ag plating. The effects of different contents of Ag@BN particles on the dynamic mechanical properties, thermal stability, and thermal conductivity of composites were examined. The results of Fourier-transform infrared spectroscopy, X-ray powder diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy analyses showed that Ag was successfully deposited on the surface of BN. The prepared Ag@BN was subjected to KH550 grafting treatment. With the increase in the content of Ag@BN/KH550, the storage modulus, thermal stability, and thermal conductivity of the composite increased. The storage modulus, decomposition temperature, and thermal conductivity of the Ag@BN/phthalonitrile composite with 20 wt.% Ag@BN/KH550 were 5.0 GPa, 539°C, and 0.80 W/(mK), respectively, which are 1.35, 1.18, and 3.33 times higher than those of pure resin, respectively. The compatibility and dispersibility of BN modified by Ag plating in phthalonitrile resin were effectively enhanced, thereby providing a potential candidate to be used at high-temperature devices with high thermal conductivity.
      Citation: High Performance Polymers
      PubDate: 2021-12-09T10:33:45Z
      DOI: 10.1177/09540083211058048
       
  • Effect of forming process on mechanical and interfacial properties for
           thermoplastic composite I-stiffened structures

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      Authors: Guangming Dai, Lihua Zhan, Chenglong Guan, Minghui Huang
      Abstract: High Performance Polymers, Ahead of Print.
      The forming process is the core factor to control the quality of thermoplastic composite components. In this paper, the common I-stiffened structures in the aerospace field were taken as the research object, and the forming process scheme was designed. Based on the prefabrication of C-shaped parts, the I-stiffened structures were prepared by the compression molding process. The influence law of molding temperature on the quality of the prefabricated C-shaped parts was explored. The time dependence of the PEEK melt viscosity was tested to provide the basis for the optimization of forming process parameters of I-stiffened structures. The influencing mechanism of thermoplastic composites repeatedly forming to the bonding strength of remelting interface was studied. The results show that repeated forming would lead to polymer aging and result in low bonding strength at the remelting interface of the I-stiffened structures. Optimizing the forming process could effectively reduce the aging of materials and improve the bonding strength of the remelting interface and overall mechanical properties of components. The research provides technical guidance for the manufacturing of complex thermoplastic composite components, especially the influence mechanism of the forming process on the bonding strength of remelting interface.
      Citation: High Performance Polymers
      PubDate: 2021-12-09T03:10:19Z
      DOI: 10.1177/09540083211051585
       
  • Effect of glass fibers length on the properties of polytetrafluoroethylene
           composites reinforced by glass fibers and graphite: Experimental and
           simulation study

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      Authors: Wei Xiao, Xin Ji, Lei Gao
      Abstract: High Performance Polymers, Ahead of Print.
      Polytetrafluoroethylene (PTFE)-based matrix composites filled with glass fibers (GF) and graphite (GR) were prepared by an internal mixer and molded using a compression mold to produce test samples. The objective was to study the mechanical and tribological properties of PTFE composites filled with different lengths of GF. The fillers of GR and GF were 5 and 15 wt.%, respectively, with the lengths of the GF of 15, 20, 25, 30, and 35-μm in the work. The mechanical performance tests and tribological tests were carried out under the same conditions. The experimental results revealed that the mechanical properties and tribological properties of the PTFE composites filled with GF and GR were associated with the lengths of GF. When the length of GF increased from 15 to 20 μm, GF could be homogeneously dispersed in the PTFE-based matrix composites and the tensile strength reached the maximum value of 21.7 ± 3.3% MPa. Also, with 20-μm long GF, the composites exhibited the lowest coefficient of friction values and wear rates compared to PTFE with GF of the other lengths. The changes in frictional heat generation and frictional force of the composites during sliding friction were simulated using the finite element method. The theoretical simulation results matched with the experimental values, which proved the accuracy of the theoretical simulations.
      Citation: High Performance Polymers
      PubDate: 2021-12-08T10:24:38Z
      DOI: 10.1177/09540083211059487
       
  • Synthesis, characterization, theoretical investigations and fluorescent
           sensing behavior of oligomeric azine-based Fe3+Chemosensors

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      Authors: Subramani Manigandan, Athianna Muthusamy, Raju Nandhakumar, Charles Immanuel David, Siddeswaran Anand
      Abstract: High Performance Polymers, Ahead of Print.
      Three azine oligomeric esters were synthesized, characterized by IR, UV, 1H, 13C{1H} and GPC technique, and applied to chemosensor application. The sensitivity response of the oligomers towards the metal ion was evaluated for a metal ion series. The results have shown selective and sensitive “turn off” fluorescence response towards Fe3+ ion in DMF/H2O (1:1, pH: 7.4, fluorophore: 5 μM) solution. The binding stoichiometry and binding constant of the fluorophores were calculated using the Stern–Volmer equation and Benesi–Hildebrand plots, respectively. The quenching of fluorophores on the addition of Fe3+ ion indicates the capability of fluorophore towards quantitative analysis of Fe3+. The dimer of oligomers was theoretically studied using DFT, B3LYP/6-311G level basic set to support and explain the quenching mechanism of LMCT, PET process and to explain the DC, AC electrical studies results. The electrical conductivity measurements of solid-state, I2 doped and undoped oligomers were carried out and the conductivity gradually increases with increase in iodine vapor contact time of oligomers. The electrical conductivity was related with band gap and charge density values of imine nitrogen obtained by Huckel calculations. The dielectric measurements at different temperatures and frequencies were made by two probe method. Among the oligomers, EBHAP has recorded a high dielectric constant at the low applied frequency of 50 Hz at 373 K due to loosely attached π bonds resulting good polarization.
      Citation: High Performance Polymers
      PubDate: 2021-12-07T01:34:57Z
      DOI: 10.1177/09540083211055675
       
  • Synthesis of novel poly(arylene ether amide) containing aliphatic ring for
           optical property

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      Authors: Shajie Luo, Junyu Dai, Xiaoyu Ji, Jialin Chen, Yue Jiang, Sixin Li, Tianzi Mao, Xiaoxia Fan
      Abstract: High Performance Polymers, Ahead of Print.
      In this work, the monomer N, N′-bis(4-fluorobenzamide)dicyclohexyl methane (BFDCM) was synthesized successfully by 4-fluorobenzoylchloride and 4,4′-diaminodicyclohexylmethane through interfacial reaction, and then the monomer BFDCM and 1,4-benzenediol (HQ) or 4.4′-biphenol (BH) were used to prepare the novel poly(arylene ether amide) (HQ-BFDCM and BH-BFDCM) containing an aliphatic ring in the main chain by nucleophilic substitution in NMP solution. These two polymers exhibited the inherent viscosities ranging from 0.828 to 1.044 dL g−1, high glass-transition temperatures (Tg) of 214.1–235.0 °C, and weight-loss temperature (T5%) of 425.2–441.3 °C. The polymers HQ-BFDCM and BH-BFDCM could completely or partly dissolve in some polar solutions, such as NMP, DMF, and so on, and they showed moderate corrosion resistance. Additionally, the obtained polymers HQ-BFDCM and BH-BFDCM exhibited good optical property, and the optical transmittances of HQ-BFDCM and BH-BFDCM were 74% and 80% at 450 nm, respectively, which showed that they could be applied to the heat-resistant optical films.
      Citation: High Performance Polymers
      PubDate: 2021-12-04T12:20:54Z
      DOI: 10.1177/09540083211052839
       
  • Highly selective sulfonated Poly (arylene ether nitrile) composite
           membranes containing copper phthalocyanine grafted graphene oxide for
           direct methanol fuel cell

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      Authors: Yan Ma, Kaixu Ren, Ziqiu Zeng, Mengna Feng, Yumin Huang
      Abstract: High Performance Polymers, Ahead of Print.
      To improve the performances of sulfonated poly (arylene ether nitrile) (SPEN)–based proton exchange membranes (PEMs) in direct methanol fuel cells (DMFCs), the copper phthalocyanine grafted graphene oxide (CP-GO) was successfully prepared via in situ polymerization and subsequently incorporated into SPEN as filler to fabricate a series of SPEN/CP-GO-X (X represents for the mass ratio of CP-GO) composite membranes. The water absorption, swelling ratio, mechanical properties, proton conductivity, and methanol permeability of the membranes were systematically studied. CP-GO possesses good dispersion and compatibility with SPEN matrix, which is propitious to the formation of strong interfacial interactions with the SPEN, so as to provide more efficient transport channels for proton transfer in the composite membranes and significantly improve the proton conductivity of the membranes. Besides, the strong π–π conjugation interactions between CP-GO and SPEN matrix can make the composite membranes more compact, blocking the methanol transfer in the membranes, and significantly reducing the methanol permeability. Consequently, the SPEN/CP-GO-1 composite membrane displayed outstanding tensile strength (58 MPa at 100% RH and 25°C), excellent proton conductivity (0.178 S cm−1 at 60°C), and superior selectivity (5.552 × 105 S·cm−3·s). This study proposed a new method and strategy for the preparation of high performance PEMs.
      Citation: High Performance Polymers
      PubDate: 2021-11-17T11:05:48Z
      DOI: 10.1177/09540083211039412
       
  • Processable poly(ether ether ketone imide)s

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      Authors: Aslam B Tamboli, Shivaji D Ghodke, Arati V Diwate, Makrand D Joshi, Vijay P Ubale, Noormahmad N Maldar
      Abstract: High Performance Polymers, Ahead of Print.
      New aromatic poly(ether ether ketone imide)s, [PEEKimide]s, were synthesized successfully from 1,3-bis-4′-(4″-aminophenoxy benzoyl) benzene and various commercially available aromatic dianhydrides, such as pyromellitic dianhydride (PMDA), 3,3′,4,4′-benzophenone tetracarboxylic dianhydride (BTDA), 3,3′,4,4′-biphenyl tetracarboxylic dianhydride (BPDA), 4,4′-oxydiphthalic anhydride (OPDA) and 4,4′-(hexafluro isoproylidene) diphthalic anhydride (HFDA), by two step polycondensation method. These PEEKimides were characterized by FT-IR, solubility in organic solvents, inherent viscosity, DSC, TGA and WXRD. Inherent viscosities of the precursor poly(ether ether ketone amic acid)s were in the range of 0.23–0.40 dl/g in DMF, indicating formation of moderate to high molecular weights. These poly(ether ether ketone imide)s showed good solubility in polar aprotic solvents such as N,N-dimethylacetamide (DMAc), N-methyl 2-pyrrolidone (NMP), N,N-dimethylformamide (DMF) and dimethyl sulphoxide (DMSO) and had glass transition temperatures in the range 245–279°C. Poly(ether ether ketone imide)s showed no weight loss below 280°C; temperatures for 10% weight loss (T10) were in the range of 406–483°C and char yields at 800°C were 17–34%, indicating their good thermal stability. All these poly(ether ether ketone imide)s were amorphous in nature, as per patterns of WXRD which exhibited diffuse broad halos at (2θ = 10–30°) and amorphous nature was reflected in polymer’s good solubility in common organic solvents.
      Citation: High Performance Polymers
      PubDate: 2021-11-05T06:31:28Z
      DOI: 10.1177/09540083211055044
       
  • Influence of charge carrier density, mobility and diffusivity on
           conductivity–temperature dependence in polyethylene oxide–based gel
           polymer electrolytes

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      Authors: Abdullaziz Abdukarimov, Ikhwan Syafiq Mohd Noor, Odiljon Mamatkarimov, Abdul Kariem Mohd Arof
      Abstract: High Performance Polymers, Ahead of Print.
      Determining the transport properties of charge carriers is essential to understand the factors that affect the conductivity trend of a polymer electrolyte system. In this work, charge carrier transport parameters of polyethylene oxide–based gel polymer electrolytes were estimated from fitting the Nyquist plot with the impedance equation, derived from the equivalent circuit that consists of a resistor in series with a constant phase element. The increase in electrolyte conductivity with temperatures from 303 K to 373 K is attributed to the increase of free ions, n (TPA+ cations and I¯ anions) and not to ionic mobility, μ. The decrease in μ with temperature is associated with the increase in the Stokes drag coefficient due to increase in ion collisions. This work explains how conductivity changes with number density of ions and mobility at various temperatures.
      Citation: High Performance Polymers
      PubDate: 2021-11-04T09:15:01Z
      DOI: 10.1177/09540083211052841
       
  • Novel poly(arylene ether nitrile) containing pendant aliphtatic ring in
           the chain: Synthesis and properties

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      Authors: Shajie Luo, Fajian Ren, Jiangang Dai, Yan Chen, Zhongzhu Yang
      Abstract: High Performance Polymers, Ahead of Print.
      Two kinds of novel poly(arylene ether nitrile)s (CPDP-DCBN and CHDP-DCBN) containing pendant aliphtatic ring were synthesized by 4,4′-cyclopentane-1,1′-diyldiphenol (CPDP) or 4,4′-cyclohexane-1,1′-diyldiphenol (CHDP) and 2,6-dichlorobenzonitrile (DCBN) in this work. The inherent viscosities of poly(arylene ether nitrile)s (PENs) were in the range of 0.701–0.806 dL g−1. The polymers showed high glass transition temperatures (Tg) of 185.4–196.4°C and weight-loss temperatures (T5%) of 447.8–454.3°C. The obtained CPDP-DCBN and CHDP-DCBN could be hot pressed into the films, which showed the tensile strengths of 82.6 MPa and 86.8 MPa, respectively. And the storage modulus of CPDP-DCBN and CHDP-DCBN were about 1.0 GPa and 1.5 GPa at 150°C, respectively. Additionally, the PENs could be dissolved in many solutions at room temperature, such as NMP and concentrated H2SO4, indicating that they had good solubility; they can be processed by the solution method. Meanwhile, the optical transmittance of CPDP-DCBN was 78.1% at 450 nm; it has potential to be applied to the heat-resistant optical film.
      Citation: High Performance Polymers
      PubDate: 2021-11-01T01:22:12Z
      DOI: 10.1177/09540083211042267
       
  • Polyimides from 2,5-bis[4-(4-aminophenoxy)benzoyl]furan and their thermal
           crosslinking reaction

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      Authors: Kai Ma, Hanzhou Jiang, Guofei Chen, Wei Wang, Yonggang Zhang
      Abstract: High Performance Polymers, Ahead of Print.
      Several polyimides were prepared via two-step polycondensation from novel 2,5-furandicarboxylic acid–based diamine, 2,5-bis[4-(4-aminophenoxy)benzoyl]furan, with commercial dianhydrides. The chemical structures of the monomers and polymers were characterized by FT-IR and NMR in detail, respectively. The polyimides exhibited high performances with 5 wt% weight loss temperatures of over 410 oC, glass transition temperatures of over 214 oC, and tensile strengths and Young’s moduli of up to 130 MPa and 3.2 GPa, respectively. The thermal crosslinking mechanism was studied by FT-IR, Raman spectroscopy, and model reaction analysis, which showed the Diels–Alder reaction between the furan group and diphenylethylene group was the main reaction. The crosslinked polyimide films showed improved solvent resistance, and thermal and mechanical properties.
      Citation: High Performance Polymers
      PubDate: 2021-10-25T12:45:41Z
      DOI: 10.1177/09540083211052270
       
  • Preparation and characterization of soluble heat-resistant polyimide films
           containing bis-N-phenyl-benzimidazole

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      Authors: Dandan Li, Chengyang Wang, Shengqi Ma, Hongwei Zhou, Ran Lu
      Abstract: High Performance Polymers, Ahead of Print.
      To prepare soluble polyimides with high temperature resistance, two new diamine monomers, namely, 2,2′-(4,4′-oxybisphenylene)-bis(1-phenyl-5-aminobenzimidazole) (5a), and 2,2′-(4,4′-hexafluoroisopropylidene)-bis(1-phenyl-5- aminobenzimidazole) (5b), were synthesized and exploited to prepare three series of poly(benzimidazole imides)s (PBIIs) by a conventional two-stage synthesis. The resulting PI films were flexible and tough, possessing high glass-transition temperatures (Tgs = 311°C–390°C), improved optical transparency, and excellent solubility. Moreover, the effect of different configuration on performance was revealed, and these data provided a feasible method to enhance both Tg and solubility of PIs by incorporating N-phenyl benzimidazole and corresponding functional moieties.
      Citation: High Performance Polymers
      PubDate: 2021-10-23T01:47:33Z
      DOI: 10.1177/09540083211036326
       
  • Novel Polyimide-block-poly(dimethyl siloxane) copolymers: Effect of time
           on the synthesis and thermal properties

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      Authors: Shengdong Xiao, Jude O Iroh
      Abstract: High Performance Polymers, Ahead of Print.
      Polyimide-block-poly(dimethyl siloxane) copolymer was synthesized by a two-step process, initiated by coupling anhydride terminated poly(amic acid), AT-PAA with amino terminated poly(dimethyl siloxane), (NH2)2-PDMS to form poly(amic acid)-block-poly(dimethyl siloxane). The resulting copolymer is then thermally treated to produce polyimide-block-poly(dimethyl siloxane), PI-PDMS. Because of the high glass transition temperature, Tg of polyimide, it is usually cured at a high temperature of about 300°C for over 2.5 h. Copolymerization of polyimide with polysiloxane, reduces the imidization temperature while maintaining high thermomechanical properties. A series of instruments were used to monitor the progress of copolymerization. The time-based analysis of the product of copolymerization enables the optimization of the structure and properties of the copolymers. The chemical structure and composition of the copolymer were studied by Fourier Transform Infrared Spectroscopy, (FT-IR). The incorporation of PDMS blocks into the copolymer and the degree of imidization of the polyimide block increased with increasing reaction time. The change in the viscosity of the copolymerizing solution was monitored by simple shear viscometry conducted with the Brookfield Viscometer. The reported increase in solution viscosity with increasing copolymerization time is associated with increasing molecular weight of the copolymer. The intrinsic viscosity of the copolymer solution was measured as a function of copolymerization time and it was found that the intrinsic viscosity of the copolymer solution increased with increasing reaction time. The glass transition temperature (Tg) and the thermal stability of the copolymer were determined by differential scanning calorimetry, DSC and thermogravimetric analysis, and TGA, respectively. Between 25°C and 420°C, the copolymers synthesized in this study show two glass transition temperatures due to the polyimide, PI block at around 380°C and another peak associated with PDMS plasticized polyimide at about 290–300°C. The two Tg peaks observed in the DSC thermogram are believed to be indicative of the structure of a block copolymer. TGA analysis shows that the thermoxidative stability of the copolymers increased with increasing reaction time, due to the incorporation of increased amount of PDMS unit into the copolymer. The combination of increasing molecular weight of copolymer, higher degree of imidization of polyimide blocks and enhanced thermoxidative stability may translate into improved flame retardancy of copolymers. This suggested enhancement in flame retardancy in air atmosphere, is believed to be due the incorporated PDMS blocks, which can be converted into silica, SiO2, a recognized thermally stable material.
      Citation: High Performance Polymers
      PubDate: 2021-10-15T01:06:23Z
      DOI: 10.1177/09540083211040479
       
  • Transparent low-flammability epoxy resins using a benzoguanamine-based
           DOPO derivative

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      Authors: Xiao Han, Rui Chen, Mei Yang, Chuanbo Sun, Kun Wang, Yinsong Wang
      Abstract: High Performance Polymers, Ahead of Print.
      We successfully prepared a highly effective flame-retardant additive called hsalbenzoguanamine phosphaphenanthrene (HDPD) through salicylaldehyde and nitrogen-rich benzoguanamine. The introduction of HDPD into epoxy resin (EP) sharply enhanced the flame retardancy of EP/HDPD thermosets. The introduction of 6 wt% HDPD into EP succeeded in reaching the V-0 rating. Limited oxygen index results revealed the high flame-retarding performance of HDPD. Cone calorimeter test data revealed that heat and smoke released from EP/6 wt% HDPD thermoset were significantly restrained. In addition, EP/6 wt% HDPD thermoset demonstrated excellent transmittance and mechanical strength. The transmittance of EP/6 wt% HDPD was assessed from 520 to 800 nm. The results showed that transmittance of EP/6 wt% HDPD were nearly 90% of the control group.
      Citation: High Performance Polymers
      PubDate: 2021-10-14T02:54:28Z
      DOI: 10.1177/09540083211049966
       
  • Adsorption and reduction of carcinogenic organics by ordered
           semi-crystalline poly-m-chloroaniline

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      Authors: Pankaj Gupta, Nakshatra Bahadur Singh, Mohit Sahni
      Abstract: High Performance Polymers, Ahead of Print.
      Poly-m-chloroaniline has been synthesized by chemical oxidative polymerization of m-chloroaniline and confirmed by spectroscopic studies. Powder X-ray diffraction and FESEM studies confirmed ordered arrangement in poly-m-chloroaniline. The peak at lower angle such as 7.09° having d spacing of 12.53 Å shows ordered structure of PmClA which was further confirmed by layered morphology in the FESEM images. FTIR spectra confirm the stretching and vibration mode of polymeric m-chloroaniline ring. BET surface area and pore diameter of PmClA were found to be 121 m2/g and 15.184 nm. Poly-m-chloroaniline was found to have better adsorption capacity toward anionic dyes over cationic dyes. The anionic dye (IC and EY) was 98 and 99% removed in just 25 min, whereas the cationic dye (MG and Rh6G) was 87 and 83% removed in 30 min. Langmuir adsorption isotherm model and pseudo second-order kinetic equation fitted the data best. Mechanism of adsorption has also been proposed. This is suggested that polymeric materials can be used for purification of water. The reduction of aromatic nitro compounds to amino compounds using organocatalyst has been done for the first time.
      Citation: High Performance Polymers
      PubDate: 2021-10-11T06:06:37Z
      DOI: 10.1177/09540083211044391
       
  • Determination of thermal degradation for high-performance thermoplastic
           composites manufactured by laser-assisted automated fibre placement

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      Authors: Dacheng Zhao, Weiping Liu, Guangquan Yue, Qinghua Song, Jiping Chen, Lijian Pan
      Abstract: High Performance Polymers, Ahead of Print.
      In in situ consolidation of thermoplastic composites by laser-assisted automated fibre placement (AFP), high laser irradiation temperature can improve the fluidity of the resin matrix, which usually enhances the performances of composites. However, it leads to a tendency for thermal degradation as the resin matrix of the composites is exposed to high temperatures for a long time. The thermal degradation behaviours of continuous carbon fibre (CF)-reinforced polyphenylene sulfide (PPS) composites during in situ consolidation by laser-assisted AFP were studied. A thermogravimetric analysis shows that the thermal degradation of CF/PPS composites is quite complex, with multi-step reactions. The thermal degradation of the composites was further analysed via kinetic methods. A thermal degradation kinetic model of the resin matrix was obtained and verified. According to the kinetic model, the thermal degradation of the composites under different placement conditions was predicted. The results were confirmed by Fourier-transform infrared spectroscopy and scanning electron microscopy. With the combination of the kinetic model, AFP in situ consolidation, and characterisation techniques, processing parameters such as laser irradiation temperature and placement speed can be adjusted and optimised.
      Citation: High Performance Polymers
      PubDate: 2021-10-09T03:43:12Z
      DOI: 10.1177/09540083211044677
       
  • An overview on the progress and development of modified sulfonated
           polyether ether ketone membranes for vanadium redox flow battery
           applications

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      Authors: Baye Gueye Thiam, Anouar El Magri, Sébastien Vaudreuil
      Abstract: High Performance Polymers, Ahead of Print.
      Vanadium redox flow batteries (VRFB) are among the most promising approaches to efficiently store renewable energies. In such battery type, Nafion is commonly used as membrane material but suffers from high vanadium crossover and cost. These drawbacks negatively influence the widespread commercial application of VRFBs. Alternative membrane materials with high performance and low cost are thus being developed to address these shortfalls. Among those, possible materials for the VRFB membrane is sulfonated polyether ether ketone (SPEEK), which recently attracted considerable attention due to its low cost, combined with mechanical and chemical stability, and ease of preparation. This review summarizes the research activities related to the development of SPEEK-based membranes for VRFB applications and gives an overview of the properties of PEEK and its sulfonated form. A critical analysis on the challenges of SPEEK-based membranes is also discussed.
      Citation: High Performance Polymers
      PubDate: 2021-10-07T01:46:10Z
      DOI: 10.1177/09540083211049317
       
  • The effects of the inclusion of 1,2,4-triazole derivatives into the main
           chains of the polyurethane urea exposed to UV radiation

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      Authors: Stefan Oprea, Violeta Otilia Potolinca
      Abstract: High Performance Polymers, Ahead of Print.
      Linear polyurethane urea containing 1,2,4-triazole segments was obtained by polyaddition of the 3,5-diamino-1,2,4-triazole (DATA) to urethane prepolymer. Also, three crosslinked polymers with different crosslinkers (2,4,6-triaminopyrimidine (TAP), glycerin (Gly), castor oil (CO)) were synthesized. Thermogravimetric analysis, of the obtained polymers, indicated good thermal stability up to 310°C. The polyurethane urea chemical structure was confirmed by FTIR analysis. The glass transition temperatures (Tg) of these polymers, measured by differential scanning calorimetry (DSC), were found in the range of −52°C to −56°C. These values were not significantly influenced by the structure of the hard domain and the intermolecular interactions. The tensile testing showed that the inclusion of 1,2,4-triazole in polyurethane structure substantially improves the tensile strength up to 58 MPa. The obtained polyurethane urea presents surface slight hydrophobic and low interfacial tension. The positive effect of the 1,2,4-triazole segment from the polymer main chain in the UV aging process of these polymer materials has been studied. After exposure to UV radiation, few changes were observed in the molecular structure, in the surface morphology and the mechanical properties.
      Citation: High Performance Polymers
      PubDate: 2021-09-24T11:11:40Z
      DOI: 10.1177/09540083211043737
       
  • Novle layered boron nitride nanosheets/cellulose nanofibers/epoxy
           composite with high thermal conductivity

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      Authors: Yunsheng Da, Jing He, Qiqi Qu, Menghan Zhu, Hua Wang, Yanyan Liu
      Abstract: High Performance Polymers, Ahead of Print.
      Studies have shown that the construction of a three-dimensional interconnected filler network is an effective method to improve the thermal conductivity of the through-plane under a lower filler load. However, huge challenges still exist in building a long-range layered filler network and reducing the thermal resistance resulting from contact between fillers and matrix. In this work, boron nitride nanosheets (BNNSs) were proposed to be connected with modified cellulose nanofibers (CNFs) to obtain a long-range layered structure filler skeleton by bidirectional freezing orientation. Then epoxy resin was dipped under vacuum condition to prepare composite with thermal conductivity up to 1.43 W/mK in through-plane when filler content is 4.3 vol%, and the composite had low thermal expansion coefficient of 64.1 ppm/°C and excellent volume resistivity up to 3.7 × 1012 Ω cm at the same time.
      Citation: High Performance Polymers
      PubDate: 2021-09-23T09:13:38Z
      DOI: 10.1177/09540083211046456
       
  • The fabrication and neutron shielding property of polyphenylene sulfide
           containing salicylic acid/Gd2O3 composites

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      Authors: Yumin He, Pengcheng Li, Haohao Ren, Xi Zhang, Xiulian Chen, Yonggang Yan
      Abstract: High Performance Polymers, Ahead of Print.
      A series of neutron absorbing materials with good neutron absorbing capacity, high strength and good thermal property were designed and prepared in this work. First of all, polyphenylene sulfide containing different mole content of salicylic acid (SAPPS) in the main chain was synthesized by nucleophilic substitution polymerization under high pressure. Then the composites with different content of nano Gd2O3 and modified PPS were prepared by melt blending method. The testing results indicated that the copolymers SAPPS were synthesized successfully, there was an interface interaction between nano Gd2O3 and the matrix without the need for surfactants or coupling agents. Additionally, the content of nano Gd2O3 had no obvious influence on the thermal property of the composites. While following with the increase of the content of nano Gd2O3, the tensile strength of the composites increased firstly and then decreased, when the content of nano Gd2O3 was 10 wt%, the tensile strength of 10%Gd2O3/5%SAPPS reached the maximum value of 74.9 MPa. The results of neutron shielding testing indicated that the content of nano-particles had a large effect on the neutron shielding rate of composites. The neutron shielding rate of 50%Gd2O3/5%SAPPS composite was up to 83%. All of these results indicated that the Gd2O3/5%SAPPS had potential to be applied to the high-temperature resistance and thermal shielding materials in nuclear and aerospace applications.
      Citation: High Performance Polymers
      PubDate: 2021-09-23T04:03:35Z
      DOI: 10.1177/09540083211021492
       
  • PVDF promotes TiO2 dispersion to obtain composite films with high
           dielectric constant and low loss

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      Authors: Mingyun Peng, Ke Li, Bingliang Huang, Jie Cheng
      Abstract: High Performance Polymers, Ahead of Print.
      A series of three-phase composite films with different filler contents were prepared by in-situ polymerization. The composite films comprise polyimide (PI), poly (vinylidene fluoride) (PVDF), and titanium dioxide (TiO2). Compared with PI/TiO2 composite films, the PI/TiO2-PVDF composite films not only get a significant increase in dielectric constant, but also own better mechanical properties. Our results show that with the loading of 50wt% PVDF particles, the dielectric constant of PI/TiO2-PVDF composite films increased from 6.5 to 18.14 at 1 MHz and room temperature, while the tensile strength of PI/TiO2-PVDF composite films increased from 45 to 72 MPa. In addition, the films maintain a low loss tangent of about 0.02. PI/PVDF composite films were also prepared. It was found that dielectric constant of PI/PVDF composite was significantly lower than that of PI/TiO2-PVDF composite films when the loading of PVDF is 50wt%.
      Citation: High Performance Polymers
      PubDate: 2021-09-23T03:57:09Z
      DOI: 10.1177/09540083211044054
       
  • Impact of quasi-isotropic raster layup on the mechanical behaviour of
           fused filament fabrication parts

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      Authors: Lovin K John, Ramu Murugan, Sarat Singamneni
      Abstract: High Performance Polymers, Ahead of Print.
      The development of fused filament fabrication has extended the range of application of additive manufacturing in various areas of research. However, the mechanical strength of the fused filament fabrication–printed parts were considerably lower than that of parts fabricated by other conventional methods, owing to the observed anisotropic behaviour and formation of voids by weak interlayer diffusion. Intense studies on the effect of design and process parameters of the printed parts on the mechanical properties have been done, whereas studies on the effect of build orientations and raster patterns needs special concern. The main aim of this work is to fabricate parts printed using quasi-isotropic laminate arrangement of rasters, achieved by a raster layup of [45/0/−45/90]s, and to compare their mechanical properties with those of the commonly used 0°/90° (cross) and 45°/−45° (crisscross) raster oriented parts. The quasi-isotropic–oriented samples were observed with improved mechanical behaviour in tensile, compressive, flexural and impact tests compared to the commonly employed raster orientations.
      Citation: High Performance Polymers
      PubDate: 2021-09-08T11:47:58Z
      DOI: 10.1177/09540083211041954
       
  • Crosslink density and mechanical property evolution during the curing of
           polyurethane-urea/sodium silicate hybrid composites

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      Authors: Yong Sun, Anqi Yu, Yuntao Liang, Gang Wang, Shuanglin Song, Wei Lu, Zhenglong He, Shaocong Meng
      Abstract: High Performance Polymers, Ahead of Print.
      In order to understand the evolution of the structure–property relationship between the crosslink density and mechanical properties of polyurethane-urea/sodium silicate (PU/SS) hybrid composites, a series of PU/SS composites with 2.5 wt% organofunctional silanes and pure PU/SS composites are investigated at different curing time. Mechanical properties, the fracture surface morphology, and thermo-mechanical properties of these PU/SS composites are characterized by electron omnipotence experiment machine, scanning electron microscope, and dynamic mechanical analysis (DMA), respectively. The mechanical test results show the strength and fracture toughness of the PU/SS composites first increase and then stabilize during cure, and the modification leads to PU/SS composites with significantly higher mechanical properties. Further, the morphology of fractured samples also reveals that the longer curing time and the modification of the PU/SS composites means a higher curing degree. Moreover, the increase in the crosslink density calculated from the DMA tests quantitatively confirmed the positive influence of the curing time and the modification in enhancing mechanical properties. In addition, it is also found that the mechanical properties of the PU/SS composites not only depend on the crosslink density but also on the well-dispersed hybrid PU/SS system.
      Citation: High Performance Polymers
      PubDate: 2021-08-31T03:27:26Z
      DOI: 10.1177/09540083211039416
       
  • High-temperature PMIA dielectric composites with enhanced thermal
           conductivity utilizing functionalized BaTiO3 nanowires–carbon nanotubes
           fillers

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      Authors: Guangyu Duan, Fengying Hu, Zhongyuan Xin, Changlong Chi, Xiang Yu
      Abstract: High Performance Polymers, Ahead of Print.
      This study reports that a novel high-temperature poly (m-phenyleneisophthalamide) (PMIA) composite with enhanced dielectric constant and thermal conductivity was prepared by filling with BaTiO3 nanowires–carbon nanotubes (BTCNs) fillers. Due to effective functionalization of BaTiO3 nanowires (BTNWs) and multi-wall carbon nanotubes (MWCNTs), the fabricated BTCNs fillers were homogeneously dispersed in PMIA matrix. The consequence displays that the dielectric constant of PMIA composite with 15 wt % BTNWs fillers increases to 27.6 at 103 Hz, which is about nine times higher than that of pure PMIA. Moreover, owing to the high thermal conductivity of MWCNTs, the thermal conductivity of PMIA with 15 wt% BTNWs fillers increases to 1.01 W/(mK). The enhanced thermal conductivity is beneficial for BTCNs/PMIA composite to dissipate the generated heat by dielectric loss. Considering these merits, this research would provide new methods and ideas for preparation of high-temperature dielectric polymer composites and reducing the internal thermal effect.
      Citation: High Performance Polymers
      PubDate: 2021-08-28T12:46:50Z
      DOI: 10.1177/09540083211041027
       
  • Thermo-oxidative aging and thermal cycling of PETI-340M composites

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      Authors: Xiaochen Li, Bo Cheng Jin, Thomas K Tsotsis, Steven Nutt
      Abstract: High Performance Polymers, Ahead of Print.
      Polyimide composites (PETI-340M) were fabricated and subjected to high-temperature aging and thermal cycling to evaluate resistance to degradation. Mechanical-degradation mechanisms and kinetics depended on aging temperature. Aging at 232°C resulted in strength loss due to polymer degradation, while intra-tow cracking was the dominant mechanism during aging at 288°C. Composite panels subjected to thermal-cycling fatigue (−54°C to 232°C) retained mechanical properties without microcracking. However, in regions containing pre-existing fabrication-induced defects (primarily voids), intra-tow microcracks were observed after thermal cycling. Unlike some polyimide composites (PMR-15), oxidative aging effects during thermal cycling were negligible. The thermo-oxidative stability and the retention of mechanical performance after thermal cycling indicates potential for long-term, high-temperature structural applications.
      Citation: High Performance Polymers
      PubDate: 2021-08-16T12:44:35Z
      DOI: 10.1177/09540083211033771
       
  • A high-performance silicon-containing arylacetylene resin with conjugated
           naphthalene rings

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      Authors: Manping Ma, Xiaotian Liu, Chuan Li, Qiaolong Yuan, Farong Huang
      Abstract: High Performance Polymers, Ahead of Print.
      2,7-Diphenyloxynaphthalene with large conjugated structure has been introduced into the main chain of silicon-containing arylacetylene resin and then poly(dimethylsilylene-ethynylenephenoxynaphthyloxyphenylene-ethynylene) (m-PPNSA-MM) was synthesized. The m-PPNSA-MM resin shows good solubility and a wide processing window. A stable three-dimensional cross-linking network formed due to thermal crosslinking reactions of acetylene groups and intermolecular π–π stacking interactions after m-PPNSA-MM was cured through the process of 180°C/2 h + 220°C/2 h + 260°C/4 h. The flexural strength and modulus of the cured m-PPNSA-MM resin at room temperature are 49.2 MPa and 2.75 GPa, respectively. The cured m-PPNSA-MM resin show high thermal stabilities, the 5% temperature of weight loss (Td5) reaches 560°C in nitrogen.
      Citation: High Performance Polymers
      PubDate: 2021-08-13T02:17:20Z
      DOI: 10.1177/09540083211035960
       
  • High fire-safety phosphorus-containing polyethylene terephthalate with
           well-balanced comprehensive performances by reactive blending with liquid
           crystalline copolyester

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      Authors: Xue-Wu Yin, Juan Xue, Xiu-Li Wang, Yu-Zhong Wang
      Abstract: High Performance Polymers, Ahead of Print.
      With increased public awareness of fire-safety, flame retardant materials have been widely used and developed. Among them, a polyester called CPET, synthesized by the copolymerization of polyethylene terephthalate and 2-carboxyethyl (phenyl) phosphinic acid, has a good fire-safety and has been employed in the manufacture of synthetic fibers. However, the fabricated fiber made of CPET simultaneously possessing good flame retardancy and mechanical properties is a dilemma. Herein, we resolve this problem through the reactive blending of CPET with a type of thermotropic liquid crystal copolyester (PPDT) and subsequently solid-state polymerization (SSP). Thus, the fire-safety of the CPET/PPDTSSP blend improves greatly. The peak heat release rate, total heat release, and total smoke release decrease by 31.2%, 16.3%, and 11.0%, respectively, compared with those of CPET. Meanwhile, the CPET/PPDTSSP shows better crystallization and mechanical properties than CPET. The strength at yield and Young’s modulus of CPET/PPDTSSP increase by 20.0% and 15.8%, respectively. This blend shows great potential in the fabrication of fire-safety fibers with high strength.
      Citation: High Performance Polymers
      PubDate: 2021-08-09T10:32:35Z
      DOI: 10.1177/09540083211028881
       
  • Enhanced hydrophilicity and antifouling performance of PES-C/emodin
           ultrafiltration membrane

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      Authors: Jinjing Li, Yiban Wu, Baining Li, Ming Hu, Jie Zhang
      Abstract: High Performance Polymers, Ahead of Print.
      In this article, an ultrafiltration membrane was fabricated from phenolphthalein polyethersulfone (PES-C) modified with emodin using a phase-inversion method. ATR-FTIR and UV-vis analysis showed that emodin had good compatibility with the PES-C ultrafiltration membrane. SEM showed that the prepared ultrafiltration membranes consisted of a porous skin layer and a macroporous support sublayer. The contact angle value of the pure PES-C ultrafiltration membrane was 77.71° and that of the PES-C ultrafiltration membrane blended with 0.105 wt.% emodin decreased to 65.71°, which explained the fact why its pure water flux significantly increased from 190 L/m2·h to 387 L/m2·h. The antifouling properties of the obtained ultrafiltration membranes were assessed by static protein adsorption, bacterial adhesion, antibacterial tests, and filtration experiments with BSA. The PES-C (13.895 wt.%)/emodin (0.105 wt.%) ultrafiltration membrane presented the lowest protein adsorption rate (1.44%), the highest flux recovery ratio (57%), and the largest inhibition zone diameter (3.0 ± 0.06 mm). Compared with that of the pure PES-C ultrafiltration membrane, the bacterial adhesion effect of the PES-C/emodin (0.105 wt.%) ultrafiltration membrane was significantly reduced. In addition, PES-C incorporated into the emodin ultrafiltration membrane had excellent stability in a deionized water system.
      Citation: High Performance Polymers
      PubDate: 2021-08-04T07:54:31Z
      DOI: 10.1177/09540083211035963
       
  • Preparation and characterization of a new type of symmetrical
           dicyclopentyl substituted cucurbit[6]uril

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      Authors: Jun Zheng, Lin Zhang, Xinan Yang, Ye Meng, Yanmei Jin, Jie Gao, Peihua Ma
      First page: 1109
      Abstract: High Performance Polymers, Ahead of Print.
      A symmetrical dicyclopentyl substituted cucurbit[6]uril (CyP2Q[6]) was synthesized, and crystallized under the conditions of 3 mol/L hydrochloric acid solution and the induction of ZnCl2. The crystal structure was characterized by X-ray single crystal diffractometer, 1H NMR and MS, and the results show that the crystal belongs to the monoclinic crystal system with P21/n space group, a = 13.095 (2), b = 33.002 (6), c = 15.770 (3), α = 90°, β = 102.828(5)°, γ = 90°, Z = 4, and a macroporous honeycomb structure appears in the crystal.
      Citation: High Performance Polymers
      PubDate: 2021-06-15T09:55:25Z
      DOI: 10.1177/09540083211023129
       
  • Benzoxazine resin as an interesting building block for advanced neutrons
           shields

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      Authors: Oussama Mehelli, Mehdi Derradji, Abdelmalek Habes, Nour Elislem Leblalta, Raouf Belgacemi, Slimane Abdous, Yasmine Izri, Wenbin Liu
      First page: 1116
      Abstract: High Performance Polymers, Ahead of Print.
      The design of lightweight neutrons shields has been restricted for quite some time to the use of the epoxy thermosets as the main building blocks. Meanwhile, the recent developments in the field of polymers suggest otherwise. Indeed, benzoxazine resins have taken the lead over the traditional thermosets in many exigent applications. Therefore, in a vision to introduce newer matrices with better performances and to further expand the applications of the benzoxazine resins into the nuclear field, the neutron shielding efficiency along with the thermal and thermomechanical performances of the neat benzoxazine polymer and its subsequent B4C-reinforced composites were investigated. The neutron shielding measurements were performed using an optimized experimental setup at NUR research reactor, Algiers. The neat benzoxazine polymer displayed almost similar thermal neutrons screening performances than the epoxy with a macroscopic cross-section (Σ) of a 0.724 cm− 1 equivalent to a mean free path (λ) of 0.957 cm. The effect of the particle amount was also studied to maximize the shielding ability of the developed materials. For instance, the benzoxazine composite containing 20 wt.% of B4C displayed the outstanding screening ratio of about 96% for a sample thickness of 13 mm. Finally, the remarkable findings were put into context by providing multifaceted comparisons with the available shielding materials.
      Citation: High Performance Polymers
      PubDate: 2021-06-17T09:32:59Z
      DOI: 10.1177/09540083211021881
       
  • Electrochemical fabrication of polyaniline/graphene paper (PANI/GP)
           supercapacitor electrode materials on free-standing flexible graphene
           paper

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      Authors: Fengyan Lv, Shanxin Xiong, Xiaoqin Wang, Jia Chu, Runlan Zhang, Ming Gong, Bohua Wu, Zhen Li, Changyong Zhu, Zhongfu Yang, Cheng Yang
      First page: 1124
      Abstract: High Performance Polymers, Ahead of Print.
      Free-standing flexible supercapacitive electrodes have practical application for wearable energy storage devices. In this paper, graphene paper (GP), a flexible electrode substrate, was prepared by one-step reduction of graphene oxide (GO) using HI solution. GP can be used independently as a flexible electrode with specific capacitance of 227 F/g. In order to make up for the shortage of GP specific capacitance storage, polyaniline (PANI) with high specific capacitance and good electrical conductivity was selected to composite with GP by electrochemical polymerization approach. This method to fabricate electrode material by direct electrochemical polymerization avoids the use of conductive binder and organic solvent. Owing to the specific capacitance contribution of PANI and GP, the PANI/GP composites exhibit higher specific capacitance when the polymerization time is 30 s and the polymerization voltage is 0.8 V. At 1 A/g current density, the specific capacitance of composite is up to 759 F/g, which is 3.34 times of neat GP.
      Citation: High Performance Polymers
      PubDate: 2021-06-17T09:34:12Z
      DOI: 10.1177/09540083211023128
       
  • Synthesis and properties of responsive self-healing polyurethane
           containing dynamic disulfide bonds

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      Authors: Qiqi Qu, Hua Wang, Jing He, Yunsheng Da, Menghan Zhu, Yanyan Liu, Xingyou Tian
      First page: 1132
      Abstract: High Performance Polymers, Ahead of Print.
      The polymers with pH responsiveness and temperature sensitivity exhibit important applications in many fields. To endow the responsive polymers with self-healing is meaningful work, which contributes to increase their service life and reduce waste of resources significantly. In this research, a series of pH-responsive polyurethanes containing dynamic disulfide bonds and carboxylic acid functional groups were prepared by mixing polycaprolactone diol (PCL), hexamethylene diisocyanate (HDI), 2,2-dimethylolbutyric acid, and bis(2-hydroxyethyl) disulfide. The structure of the polymer was confirmed by some characterization methods such as infrared absorption spectroscopy, Raman scattering spectroscopy, X-ray diffraction, and differential scanning calorimetry. Many performances of the polymer such as the contact angle, thermal stability, mechanics, and self-healing properties can be adjusted by changing the functional units of polyurethanes. The dynamic disulfide bonds in the main chain were observed no harm to the pH response performance, instead which were beneficial to the promotion of heat resistance, tensile properties, and self-healing performance of polyurethane. The elongation at break and the tensile strength are increased by 85.3% and 54.9%, respectively. All the polyurethane exhibited considerable self-healing effects at 110°C, with the highest healing efficiency reaching 93.7%, as a result of the dissociation of hydrogen bonds and the exchange reaction of disulfide bonds.
      Citation: High Performance Polymers
      PubDate: 2021-06-18T09:13:35Z
      DOI: 10.1177/09540083211022818
       
  • Influence of resin curing cycle on the deformation of filament wound
           composites by in situ strain monitoring

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      Authors: Xiaodong Chen, Yong Li, Dajun Huan, Wuqiang Wang, Yang Jiao
      First page: 1141
      Abstract: High Performance Polymers, Ahead of Print.
      The residual stress of metal liners wrapped by composite materials has a significant influence on the service performance of rotating parts, such as flywheel rotors and motor jackets. However, the deformation of the liners, the flow of resins, and the temperature variation during the winding process make it difficult to predict and control this residual stress. In this paper, the process-induced strains were monitored online by a strain gauge with the help of a wireless strain meter. The evolution of this strain during the manufacturing process was fully discussed. A rapid curing resin system was used and its curing properties were tested by differential scanning calorimetry. The mechanical properties of the resin matrix and its composite were characterized. The effect of the curing cycle on the evolution of the residual strain was discussed in detail through comparative experiments. The experimental results show that the use of infrared radiation has a significant advantage regarding residual stress accumulation. This advantage is greater when carbon fiber is used than when glass fiber is used. The prestress in composites of glass fiber and carbon fiber increases by 5.9% and 41.7%, respectively, after cooling.
      Citation: High Performance Polymers
      PubDate: 2021-06-28T09:36:21Z
      DOI: 10.1177/09540083211026359
       
  • Thermomechanical properties of silica–epoxy nanocomposite modified by
           hyperbranched polyester: A molecular dynamics simulation

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      Authors: Jianwen Zhang, Dongwei Wang, Lujia Wang, Wanwan Zuo, Xiaohua Ma, Shuai Du, Lijun Zhou
      First page: 1153
      Abstract: High Performance Polymers, Ahead of Print.
      In this article, pure epoxy resin and silica–epoxy nanocomposite models were established to investigate the effects of hyperbranched polyester on microstructure and thermomechanical properties of epoxy resin through molecular dynamics simulation. Results revealed that the composite of silica can improve the thermomechanical properties of nanocomposites, including the glass transition temperature, thermal conductivity, and elastic modulus. Moreover, the thermomechanical properties were further enhanced through chemical modification on the silica surface, where the effectiveness was the best through grafting hyperbranched polyester on the silica surface. Compared with pure epoxy resin, the glass transition temperature of silica–epoxy composite modified by silica grafted with hyperbranched polyester increased by 38 K. The thermal conductivity increased with the increase of temperature and thermal conductivity at room temperature increased to 0.4171 W/(m·K)−1 with an increase ratio of 94.3%. Young’s modulus, volume modulus, and shear modulus all fluctuated as temperature rise with a down overall trend. They increased by 44.68%, 29.52%, and 36.65%, respectively, when compared with pure epoxy resin. At the same time, the thermomechanical properties were closely related to the microstructure such as fractional free volume (FFV), mean square displacement (MSD), and binding energy. Silica surface modification by grafting hyperbranched polyester reduced the FFV value and MSD value most and strengthened the combination of silica and epoxy resin matrix the best, resulting in the best thermomechanical properties.
      Citation: High Performance Polymers
      PubDate: 2021-07-21T02:08:08Z
      DOI: 10.1177/09540083211032383
       
  • Effect of the content of silane-functionalized boron carbide on the
           mechanical and wear performance of B4C reinforced epoxy composites

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      Authors: Sunny Bhatia, Sabah Khan, Surjit Angra
      First page: 1165
      Abstract: High Performance Polymers, Ahead of Print.
      This article presents the mechanical, physical, and tribological properties of the boron carbide (B4C) reinforced epoxy matrix composites (BEMCs). The BEMC samples were prepared with various B4C concentration of 0%, 1%, 2%, 3%, and 5%. B4C particles were treated with a silane coupling agent to ensure efficient adhesion with epoxy. The influence of a range of parameters (particle loading, sliding speed, sliding distance, and normal load) on the wear and friction behavior of BEMCs were evaluated by conducting wear tests under dry sliding conditions on a pin-on-disc wear test set-up. The addition of B4C to the epoxy polymer improved the wear resistance of the composites. Maximum wear resistance and coefficient of friction were observed for the composite with the highest percentage of B4C (5%). The specific wear rate was reduced on increasing load and sliding distance and increased with the sliding velocity. Mechanical properties including compression strength, flexural strength, and impact energy, along with physical properties such as density and hardness, were also evaluated. B4C particles improved the hardness, density, flexural and compression strength, and impact resistance of the composites. Scanning electron microscope (SEM) analysis of the worn-out surfaces and flexural fractured surfaces was carried out to predict the possible wear and fracture mechanisms. Micro-ploughing, abrasion, and adhesion were the wear mechanisms in BEMCs. Under the flexural loads, particulate de-bonding, pull-out, and brittle fracture of the matrix were the governing failure mechanisms.
      Citation: High Performance Polymers
      PubDate: 2021-07-21T01:55:43Z
      DOI: 10.1177/09540083211031129
       
  • Enhanced crystallization behaviors and dielectric performance of
           poly(vinylidene fluoride) film by induced polyamide-1

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      Authors: Dandan Yuan, Rundi Yang, Yuanting Xu, Xufu Cai
      First page: 1181
      Abstract: High Performance Polymers, Ahead of Print.
      Poly(vinylidene fluoride) (PVDF)-based composites attract tremendous attention as dielectric materials. However, their development has been limited due to the raised problem in the in-homogeneous polymer composites. In this work, a novel PVDF-based film incorporated with polyamide-1, containing the highest density of dipole among all polyamides, was prepared to improve the crystallization behaviors and dielectric properties. The results showed that the optimal concentration of polyamide-1 in PVDF was 6 wt.%. The crystallization rate of PVDF was improved in the presence of polyamide-1. Interestingly, the polyamide-1 was conductive to the formation of β form crystal of PVDF, which exhibited great electric performance. The dielectric constant of PVDF increased sharply and loss tangent still kept at a low level of 0.03@100 Hz when the concentration of polyamide-1 was 6 wt.%. This work may provide a new direction to design dielectric materials for PVDF blends.
      Citation: High Performance Polymers
      PubDate: 2021-07-22T06:32:21Z
      DOI: 10.1177/09540083211031138
       
  • Preparation and properties of bismaleimide resin blended with
           alkynyl-terminated modifiers

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      Authors: Hui Zhang, Linxiang Wang, Qiaolong Yuan, Qing Zheng, Liqiang Wan, Farong Huang
      First page: 1192
      Abstract: High Performance Polymers, Ahead of Print.
      A kind of modified bismaleimide resin, with good processability, heat resistance, and impact strength was developed, using 4,4′-dipropargyloxydiphenyl ether (DPEDPE), N-(4-propargyloxyphenyl)maleimide (4-PPM), and 3-ethynylphenyl maleimide (3-EPM) as modifiers. The DPEDPE, 4-PPM, and 3-EPM were synthesized and characterized by Fourier transform infrared spectroscopy (FTIR) and 1H-nuclear magnetic resonance (1H NMR), and used to modify the N,N′-(4,4′-diphenylmethane)bismaleimide (BDM)/2,2′-diallyl bisphenol A (DABPA) resin system (BD) to obtain the different blend resin systems of DPEDPE-modified BD (BDD), 4-PPM-modified BD (BDP), and 3-EPM-modified BD (BDE). The curing temperature of BD resin increases with increase of the alkynyl-terminated modifier content. The processability of BD resin was improved with addition of the propargyloxy-terminated compounds. The temperature of 5% weight loss, residual yield at 800°C and glass transition temperature of the cured BD resin increase with increase of the alkynyl-terminated modifier content and can reach 443°C, 46.7% and higher than 380°C. The tensile strength of the cured BD resin decreases with increase of alkynyl-terminated modifier content. The impact strength of the cured BD resin increases with increase of the propargyloxy-terminated compound content and can increase by 65%. The tensile strength, elastic modulus, and impact strength of the cured BD resin blended with DPEDPE can be 73.7 MPa, 4.1 GPa, and 19.6 kJ m−2, respectively. Moreover, the cured BD resin blended with DPEDPE has good water absorption resistance.
      Citation: High Performance Polymers
      PubDate: 2021-07-31T12:15:26Z
      DOI: 10.1177/09540083211034118
       
  • Photocatalytic self-cleaning properties of m-phenylene isophthalamide
           membranes enhanced by immobilization of GO-ZnO-Ag for dye wastewater
           disposal

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      Authors: Huan-Yin Xie, Zhen Chen, Yi-Jing Li, Gui-E Chen, Hai-Fang Mao, Zhen-Liang Xu
      First page: 1205
      Abstract: High Performance Polymers, Ahead of Print.
      Drawing self-cleaning technology into polymer membranes offers an extensive solution to overcome the membrane fouling obstacle. Herein, the GO-ZnO-Ag nano-hybrid particles with photocatalytic activity prepared via the microwave hydrothermal method were immobilized in poly(m-phenylene isophthalamide) (PMIA) membranes. Not only was the thorny issue in catalyst recovery avoided, but also the satisfactory photocatalytic self-cleaning performance of the polymer membrane was awarded. GO and noble metal silver nanoparticles (AgNPs) acted as a conductive electron transfer carrier and an electron host, respectively, which hindered the recombination rate of excited electrons and holes on ZnO under UV light. The UV-driven PMIA membrane photodegradation rates of MB and Cr(VI) were up to 97.2% and 94.3%, respectively, at 150 min on photodegradation kinetics. Also, MB was completely degraded at 180 min. For MB and Cr(VI) mix solutions, their degradation efficiencies were 78.1% and 71%, respectively. The BSA rejection rate of the modified polymer membrane was 93.8%, and the water flux was 408.8 (L·m−2·h−1). Permeability was maintained at a high level after repeated use. Therefore, the newly designed PMIA/GO-ZnO-Ag series membranes could expand the application of polymers in wastewater disposal industry.
      Citation: High Performance Polymers
      PubDate: 2021-07-31T06:24:06Z
      DOI: 10.1177/09540083211028876
       
  • Wetting characteristics of polymer adhesives with different chain bending
           stiffness

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      Authors: Wenhao Sha, Jimin Fu, Fenglin Guo
      First page: 1220
      Abstract: High Performance Polymers, Ahead of Print.
      Polymer adhesives are widely used in daily applications and in industry owing to their flexibility and overall non-toxicity, particularly in interfacial adhesion. The spreading of polymer adhesives on adherend is one of the essential considerations for the interfacial adhesion of polymer adhesives, which is strongly related to their wetting behaviors. While relationships between polymer microstructure and adhesion have been investigated in previous studies, it remains challenging to unveil the effect of polymer microstructure on wettability. To address this issue, here we utilize coarse-grained molecular dynamics (CGMD) simulations to systematically elucidate how the wettability of a polymer adhesive droplet on a surface depends on bending stiffness. The wetting dynamics and the contact angle are studied to show the evolution of morphology of droplets during the wetting process. The results indicate the wettability is weakened by the increase of bending stiffness of polymer chain. Detailed thermodynamic property analysis is further conducted, revealing that the adhesion between the polymer droplet and substrate deteriorates due to the decline of wettability. Interestingly, we observe such deterioration becomes more significant by both increasing the temperature and decreasing the bending stiffness. Our study sheds light on the dependence of chain bending stiffness and temperature on the wetting behavior of polymer adhesive droplets, and offers insights, which, upon experimental validation can then be used for the design of adhesives or hydrogels.
      Citation: High Performance Polymers
      PubDate: 2021-08-03T04:02:54Z
      DOI: 10.1177/09540083211035016
       
 
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