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  Subjects -> ENGINEERING (Total: 1953 journals)
    - CHEMICAL ENGINEERING (153 journals)
    - CIVIL ENGINEERING (148 journals)
    - ELECTRICAL ENGINEERING (81 journals)
    - ENGINEERING (1110 journals)
    - ENGINEERING MECHANICS AND MATERIALS (290 journals)
    - HYDRAULIC ENGINEERING (45 journals)
    - INDUSTRIAL ENGINEERING (52 journals)
    - MECHANICAL ENGINEERING (74 journals)

CHEMICAL ENGINEERING (153 journals)                  1 2     

ACS Combinatorial Science     Full-text available via subscription   (Followers: 8)
Acta Crystallographica Section B: Structural Science, Crystal Engineering and Materials     Hybrid Journal   (Followers: 3)
Acta Polymerica     Hybrid Journal   (Followers: 6)
Additives for Polymers     Full-text available via subscription   (Followers: 19)
Adhesion Adhesives & Sealants     Hybrid Journal   (Followers: 4)
Advanced Chemical Engineering Research     Open Access   (Followers: 8)
Advanced Powder Technology     Hybrid Journal   (Followers: 12)
Advances in Chemical Engineering     Full-text available via subscription   (Followers: 15)
Advances in Chemical Engineering and Science     Open Access   (Followers: 21)
Advances in Polymer Technology     Hybrid Journal   (Followers: 11)
African Journal of Pure and Applied Chemistry     Open Access   (Followers: 2)
Annual Review of Analytical Chemistry     Full-text available via subscription   (Followers: 9)
Annual Review of Chemical and Biomolecular Engineering     Full-text available via subscription   (Followers: 10)
Anti-Corrosion Methods and Materials     Hybrid Journal   (Followers: 4)
Applied Petrochemical Research     Open Access   (Followers: 3)
Asia-Pacific Journal of Chemical Engineering     Hybrid Journal   (Followers: 6)
Biochemical Engineering Journal     Hybrid Journal   (Followers: 8)
Biomass Conversion and Biorefinery     Partially Free   (Followers: 5)
BMC Chemical Biology     Open Access   (Followers: 4)
Brazilian Journal of Chemical Engineering     Open Access   (Followers: 2)
Bulletin of the Chemical Society of Ethiopia     Open Access   (Followers: 1)
Carbohydrate Polymers     Hybrid Journal   (Followers: 8)
Catalysts     Open Access   (Followers: 6)
Chemical and Petroleum Engineering     Hybrid Journal   (Followers: 7)
Chemical and Process Engineering     Open Access   (Followers: 3)
Chemical and Process Engineering Research     Open Access   (Followers: 5)
Chemical Communications     Full-text available via subscription   (Followers: 29)
Chemical Engineering & Technology     Hybrid Journal   (Followers: 24)
Chemical Engineering and Processing: Process Intensification     Hybrid Journal   (Followers: 10)
Chemical Engineering and Science     Open Access   (Followers: 2)
Chemical Engineering Communications     Hybrid Journal   (Followers: 10)
Chemical Engineering Journal     Hybrid Journal   (Followers: 18)
Chemical Engineering Research and Design     Hybrid Journal   (Followers: 15)
Chemical Engineering Science     Hybrid Journal   (Followers: 10)
Chemical Geology     Hybrid Journal   (Followers: 9)
Chemical Papers     Hybrid Journal   (Followers: 3)
Chemical Product and Process Modeling     Full-text available via subscription   (Followers: 3)
Chemical Reviews     Full-text available via subscription   (Followers: 264)
Chemical Society Reviews     Full-text available via subscription   (Followers: 27)
Chemical Technology     Open Access   (Followers: 4)
ChemInform     Hybrid Journal   (Followers: 3)
Chemistry & Industry     Hybrid Journal   (Followers: 2)
Chemistry Central Journal     Open Access   (Followers: 5)
Chemistry of Materials     Full-text available via subscription   (Followers: 177)
Chemometrics and Intelligent Laboratory Systems     Hybrid Journal   (Followers: 6)
ChemSusChem     Hybrid Journal   (Followers: 7)
Chinese Chemical Letters     Full-text available via subscription   (Followers: 1)
Chinese Journal of Chemical Engineering     Full-text available via subscription   (Followers: 3)
Chinese Journal of Chemical Physics     Hybrid Journal   (Followers: 1)
Coke and Chemistry     Hybrid Journal  
Coloration Technology     Hybrid Journal   (Followers: 1)
Computational Biology and Chemistry     Hybrid Journal   (Followers: 8)
Computer Aided Chemical Engineering     Full-text available via subscription   (Followers: 2)
Computers & Chemical Engineering     Hybrid Journal   (Followers: 6)
Corrosion Reviews     Full-text available via subscription   (Followers: 4)
Crystal Research and Technology     Hybrid Journal   (Followers: 2)
Current Opinion in Chemical Engineering     Open Access   (Followers: 3)
Education for Chemical Engineers     Hybrid Journal   (Followers: 4)
European Polymer Journal     Hybrid Journal   (Followers: 41)
Fibers and Polymers     Full-text available via subscription   (Followers: 3)
Focusing on Modern Food Industry     Open Access   (Followers: 3)
Frontiers of Chemical Science and Engineering     Hybrid Journal   (Followers: 1)
Geochemistry International     Hybrid Journal  
Handbook of Powder Technology     Full-text available via subscription   (Followers: 2)
High Performance Polymers     Hybrid Journal  
Indian Chemical Engineer     Hybrid Journal   (Followers: 3)
Indian Journal of Chemical Technology (IJCT)     Open Access   (Followers: 12)
Industrial & Engineering Chemistry     Full-text available via subscription   (Followers: 9)
Industrial & Engineering Chemistry Research     Full-text available via subscription   (Followers: 16)
Industrial Chemistry Library     Full-text available via subscription   (Followers: 4)
International Journal of Chemical and Petroleum Sciences     Open Access   (Followers: 1)
International Journal of Chemical Engineering     Open Access   (Followers: 6)
International Journal of Chemical Reactor Engineering     Full-text available via subscription   (Followers: 3)
International Journal of Chemical Technology     Open Access   (Followers: 3)
International Journal of Chemoinformatics and Chemical Engineering     Full-text available via subscription   (Followers: 2)
International Journal of Food Science     Open Access   (Followers: 2)
International Journal of Industrial Chemistry     Open Access  
International Journal of Polymeric Materials     Hybrid Journal   (Followers: 3)
International Journal of Science and Engineering     Open Access   (Followers: 7)
International Journal of Waste Resources     Open Access   (Followers: 4)
ISRN Chemical Engineering     Open Access   (Followers: 4)
ISRN Polymer Science     Open Access   (Followers: 11)
Journal of Applied Crystallography     Hybrid Journal   (Followers: 4)
Journal of Applied Electrochemistry     Hybrid Journal   (Followers: 6)
Journal of Applied Polymer Science     Hybrid Journal   (Followers: 167)
Journal of Biomaterials Science, Polymer Edition     Hybrid Journal   (Followers: 8)
Journal of Chemical & Engineering Data     Full-text available via subscription   (Followers: 6)
Journal of Chemical Ecology     Hybrid Journal   (Followers: 1)
Journal of Chemical Engineering     Open Access   (Followers: 3)
Journal of Chemical Engineering and Materials Science     Open Access  
Journal of Chemical Science and Technology     Open Access   (Followers: 1)
Journal of Chemical Sciences     Partially Free   (Followers: 15)
Journal of Chemical Technology & Biotechnology     Hybrid Journal   (Followers: 2)
Journal of Chemical Theory and Computation     Full-text available via subscription   (Followers: 9)
Journal of Coatings     Open Access   (Followers: 2)
Journal of Crystallization Process and Technology     Open Access   (Followers: 5)
Journal of Food Measurement and Characterization     Hybrid Journal  
Journal of Fuel Chemistry and Technology     Full-text available via subscription   (Followers: 5)
Journal of Fuels     Open Access  
Journal of Geochemical Exploration     Hybrid Journal  

        1 2     

Journal Cover High Performance Polymers
   Follow    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
     ISSN (Print) 0954-0083 - ISSN (Online) 1361-6412
     Published by Sage Publications Homepage  [738 journals]   [SJR: 0.344]   [H-I: 28]
  • Preparation and electrochemical performances of hexacyanoferrate-doped
           poly(3,4-ethylenedioxythiophene) hydrogel
    • Authors: Han, Y; Guo, Y, Shen, M, Duan, P, Yuan, Z, Zhang, M.
      Pages: 499 - 506
      Abstract: In this article, potassium hexacyanoferrate (K3Fe(CN)6) was introduced into poly(3,4-ethylenedioxythiophene) (PEDOT) hydrogel by in situ polymerization to prepare K3Fe(CN)6-doped PEDOT hydrogel. The specific capacitance of PEDOT hydrogel was efficiently increased by the doping effect of K3Fe(CN)6. The increase in capacitance achieved by introducing K3Fe(CN)6 into PEDOT hydrogel was attributed to the doping effect of anionic ferricyanide/ferrocyanide couple. The specific capacitance of PEDOT hydrogel increased from 38 F g–1 to the maximum value of 98 F g–1 (current density = 500 mA g–1) when the concentration of K3Fe(CN)6 reached 5 mM. On the basis of cycle life tests, the capacitance retention of about 75% for the doped PEDOT hydrogel after 5000 cycles suggested a high cycle stability of redox-active PEDOT hydrogel and its potential as an electrode material for supercapacitor applications.
      PubDate: 2014-07-14T04:44:58-07:00
      DOI: 10.1177/0954008314520788|hwp:master-id:sphip;0954008314520788
      Issue No: Vol. 26, No. 5 (2014)
       
  • Influence of morphology on the flame retardancy of
           polystyrene/nylon-6/ammonium polyphosphate/clay blends
    • Authors: Lu, C; Yang, D, Cao, Q.-Q, Huang, X.-H, Liu, J.-C, Zhang, Y.-Q.
      Pages: 507 - 516
      Abstract: Ammonium polyphosphate (APP) and clay were utilized to flame retard polystyrene/nylon 6 (PS/PA6) blends. X-ray diffraction and transmission electron microscopy (TEM) results showed that clay formed exfoliated structures in PS/PA6/APP/clay. The results of Fourier transform infrared spectra and TEM indicated that APP and clay were exclusively dispersed in the PA6 phase. The influences of the distribution of APP and clay in PS/PA6 blends and the continuity of the (PA6 + APP) phase on flame retardancy were investigated. The flame-retardant properties were evaluated by limiting oxygen index (LOI), vertical flammability test, and cone calorimeter tests. For blends with a continuous PA6 + APP phase, the decrease of PA6 content caused an increase in LOI values from 26 to 34% and a remarkable reduction of the heat release rate. Results of thermogravimetric analysis indicated that the localization of APP and clay in the PA6 phase caused an increase in APP concentration in the PA6 phase with decreasing PA6 content, resulting in the rapid formation of intumescent charred layer, which augmented the flame retardancy. The transformation of (PA6 + APP) phase morphology from a continuous state to a discontinuous state at a PA6 content of below 40% (w/w) was observed. Meanwhile, the flame-retardant properties were decreased as the PA6 content decreases. The discontinuous intumescent charred layer thus formed and the inhibiting action of clay on the residue char from expanding could be responsible for the deterioration of flame-retardant properties, which were also confirmed by scanning electron microscopy and the aspect of intumescent charred layer.
      PubDate: 2014-07-14T04:44:58-07:00
      DOI: 10.1177/0954008314520789|hwp:master-id:sphip;0954008314520789
      Issue No: Vol. 26, No. 5 (2014)
       
  • Investigation on cyclization process of co-polyimides containing
           2-(4-aminophenyl)-5-aminobenzimidazole units
    • Authors: Dong, J; Xu, Y, Xia, Q, Yin, C, Zhang, Q.
      Pages: 517 - 525
      Abstract: As one type of high-performance polymers, polyimides have been extensively used in various fields. The cyclization reaction plays a significant role in the change of the polymeric chemical structure and physical properties. In this work, a series of random co-poly(amic acid)s (PAAs) were synthesized by introducing an aromatic heterocyclic diamine monomer (2-(4-aminophenyl)-5-aminobenzimidazole (BIA)) into the homopolyimide backbones of pyromellitic dianhydride (PMDA) and 4,4'-oxydianiline (ODA). Fourier transform infrared (FTIR) spectroscopy was employed to study the cyclization kinetics in the temperature range of 180–300°C. The results indicate that the addition of BIA decreases the cyclization rates, which is mainly attributed to the rigid-rod structure of the BIA. The mechanism of thermal imidization of the solid state co-PAA was also studied by FTIR using two-dimensional correlation spectroscopy method. The signs of the cross peaks in asynchronous spectra suggested that the imide-related modes changed prior to the amide mode, which indicates that cyclization occurred before the amide proton was abstracted. The result illustrates the truth that the introduction of BIA units into PMDA-ODA segments obviously increases the barrier for the meta-segment of PAA into corresponding polyimide, which is the essential reason for the decreasing cyclization rate.
      PubDate: 2014-07-14T04:44:58-07:00
      DOI: 10.1177/0954008314520790|hwp:master-id:sphip;0954008314520790
      Issue No: Vol. 26, No. 5 (2014)
       
  • Preparation of phosphorus-containing epoxy emulsion and flame retardancy
           of its thermoset
    • Authors: Qin, Y; Xu, G, Wang, Y, Hu, J.
      Pages: 526 - 531
      Abstract: In this study, the effects of the opening ratio and neutralization degree of diethanolamine to the formation of epoxy emulsion were examined. o-Cresol formaldehyde epoxy resin was modified with 9,10-dihydro-9-xa-10-phosphaphenanthrene-10-oxide and diethanolamine and was then neutralized by acetic acid to obtain a phosphorus-containing epoxy emulsion by the phase inversion method. The microstructure and size distribution of the epoxy latex were characterized using transmission electron microscopy and the Malvern particle sizer, respectively. The glass transition temperatures of epoxy resins and their thermosets were characterized using differential scanning calorimetry. The flame retardancy of the phosphorus-containing epoxy thermosets was tested by the UL-94 test method, limiting oxygen index (LOI), and thermogravimetric analysis (TGA). The result shows that when the diethanolamine opening ratio was 22.5% and neutralization degree was 100.0%, a stable epoxy emulsion was obtained. When the phosphorus content of the epoxy resin was 2.5 wt%, the LOI value of the epoxy thermoset can reach 36.8 and pass the V-0 rating of the UL-94 test. TGA and scanning electron microscopy images of char residue of epoxy thermosets show that the flame-retardant mechanism of the phosphorus-containing epoxy thermoset was mainly attributed to a condensed-phase mechanism.
      PubDate: 2014-07-14T04:44:58-07:00
      DOI: 10.1177/0954008314522279|hwp:master-id:sphip;0954008314522279
      Issue No: Vol. 26, No. 5 (2014)
       
  • Immiscible blends of sulfonated polyetheretherketone and fluorinated
           polyimide for proton exchange membranes
    • Authors: Cao, X; Jing, L, Liu, Y, Hu, W, Jiang, Z, Liu, B.
      Pages: 532 - 539
      Abstract: Both multitrifluoromethylated polyimide (12F-PI) and sulfophenylated polyetheretherketone (Ph-SPEEK) were synthesized in order to build immiscible blends for proton exchange membranes (PEMs). The 12F-PI/Ph-SPEEK blend membranes had improved dimensional stability and oxidation stability in comparison with pure Ph-SPEEK. Despite the introduction of the hydrophobic 12F-PI content, the proton conductivity of blends 1 and 2 showed significantly increased proton conductivity at 80–100°C. The interesting phase-separation morphology, in which the "inorganic-like" particles formed by 12F-PI dispersed in Ph-SPEEK, was observed. This morphology similar to inorganic–organic blends could be highly related to the big differences in the hydrophobicity/hydrophilicity and backbones of two polymers. The obtained results suggest that this series of blend membranes may be potential PEMs for fuel cells.
      PubDate: 2014-07-14T04:44:58-07:00
      DOI: 10.1177/0954008314522668|hwp:master-id:sphip;0954008314522668
      Issue No: Vol. 26, No. 5 (2014)
       
  • Phthalonitrile-functional multiple arylene ether nitrile-containing
           phthalazinone moiety: facile synthesis, curing, and properties
    • Authors: Fu, X; Yu, G, Liu, C, Wang, J, Pan, C, Jian, X.
      Pages: 540 - 549
      Abstract: This article discloses a series of processable multiple phthalazinone-based ether nitriles with various contents of phthalonitrile ends (compounds 4a–4e) and compares the cyclization feasibility of terminal phthalonitrile and pendant cyano group. Compounds 4a–4e were synthesized by facile polycondensation of excess 4-(4-hydroxyphenyl)-2,3-phthalazine-1-one (compound 1) with 2,6-difluorobenzonitrile (compound 2), followed by end-capping of 4-nitrophthalonitrile (compound 4). Their number-averaged molecular weights (M ns) and glass transitions can be well tailored by adjusting reactant ratio. Compounds 4a-4e are readily soluble in N-methyl-2-pyrrolidone, N,N-dimethylacetamide, dimethyl sulfoxide, N,N-dimethylformamide, and chloroform and hence can be processed either from their solutions or from melts. On mixing with trace amount of bis(4-aminophenyl)sulfone (compound 5), all oligomers were cross-linked to insoluble networks (compounds 6a-6d) except the high-molecular-weight 4e with the lowest phthalonitrile content. The phthalonitrile is found to be an effectively reactive site for cross-linking, whereas the pendant cyano group in multiple ether nitriles hardly undergoes any reaction confirmed by model reaction. Compounds 6a-6d maintain good structural integrity upon heating to 450°C and exhibit superior thermal stabilities compared with the known phthalazinone polymers. Compounds 6a-6d exhibit high flexural strength (98–111 MPa) as well as limited water absorption (2.2–2.7 wt%) under ambient conditions over a course of 30 days, permitting them to be promising candidates for organic electronics and automotives.
      PubDate: 2014-07-14T04:44:58-07:00
      DOI: 10.1177/0954008314522822|hwp:master-id:sphip;0954008314522822
      Issue No: Vol. 26, No. 5 (2014)
       
  • Structurally modified aromatic sulfone polymer nanocomposites as
           polyelectrolyte membranes
    • Authors: Unnikrishnan, L; Mohanty, S, Nayak, S. K.
      Pages: 550 - 560
      Abstract: A candid approach to analyze the prospects of organic–inorganic nanocomposites as polyelectrolytes has been presented in this communication. Structurally modified aromatic sulfone polymer, polysulfone, was successfully prepared through modification with trimethyl silyl chlorosulfonate, which was confirmed from Fourier transform infrared spectrographs. Different classes of nanofillers like layered silicates and inorganic oxides were reinforced in the modified macromolecular system using solvent casting technique. A comparative study was performed to evaluate the effectiveness of filled polyelectrolyte membranes in a direct methanol fuel cell operated at 60°C with 1.0 M methanol feed. Atomic force micrographs revealed the phase morphology, responsible for this behaviour. The variation in ion transfer behavior as a function of structural modification and filler composition was also conducted. Furthermore, supportive information for these characterizations were derived from morphological (x-ray diffractometry), thermal (thermogravimetric analysis), and liquid uptake studies.
      PubDate: 2014-07-14T04:44:58-07:00
      DOI: 10.1177/0954008314522839|hwp:master-id:sphip;0954008314522839
      Issue No: Vol. 26, No. 5 (2014)
       
  • Synthesis and characterization of poly(pyridine-imide)s with tert-butyl
           substituents
    • Authors: Lu, Y; Wu, Y, Xiao, G, Dong, Y, Zhao, H, Hu, Z.
      Pages: 561 - 568
      Abstract: The aromatic diamine monomer containing a pyridine heterocyclic group and a tert-butyl substituent, 4-[(4'-tert-butyl)phenyl]-2,6-bis(4-aminophenyl)pyridine (BPAP), was successfully synthesized by a modified Chichibabin reaction of 4-nitro-acetophenone and 4-tert-butyl benzaldehyde, followed by a reduction of the resulting dinitro compound 4-[(4'-tert-butyl)phenyl]-2,6-bis(4-nitrophenyl)pyridine with palladium/carbon and hydrazine monohydrate, successively. A series of poly(pyridine–imide)s were prepared from the diamine BPAP with the alicyclic anhydride 1,2,3,4-cyclobutanetetracarboxylic dianhydride, aromatic anhydride pyromelitic dianhydride, 3,3',4,4'-biphenyl tetracarboxylic dianhydride, and 4,4'-oxydiphthalic anhydride in N,N-dimethylformamide (DMF) via the conventional two-step method and further chemical imidization to obtain poly(pyridine-imide) powders. Due to the introduction of tert-butyl group, the polyimides (PIs) derived from BPAP were amorphous and displayed good solubility in amine-type polar solvents, such as DMF, dimethyl sulfoxide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone. Because of the presence of rigid triphenylpyridine units and bulky substituents, the final PIs held a good thermal stability with 10% weight loss temperatures above 504°C and left more than 55% residue even at 700°C under nitrogen atmosphere. The effect of tert-butyl substituents on the properties of the PIs was studied by comparing with 4-phenyl-2,6-bis(4-nitrophenyl)pyridine. These PIs exhibited some fluorescent properties because of the triphenylpyridine units, and the chemical structure of dianhydrides took an effect on the fluorescent property of these PIs.
      PubDate: 2014-07-14T04:44:58-07:00
      DOI: 10.1177/0954008314523054|hwp:master-id:sphip;0954008314523054
      Issue No: Vol. 26, No. 5 (2014)
       
  • Synthesis of new autophotosensitive semiaromatic hyperbranched polyimides
           with excellent mechanical properties and low birefringences
    • Authors: Li, Y; Liu, C, Jiao, L, Song, G, Zhao, X, Dang, G.
      Pages: 569 - 577
      Abstract: A series of autophotosensitive semiaromatic hyperbranched polyimides (PIs) were prepared by (A2 + B3)-type method and endcapped with 2,6-dimethylaniline. The photosensitive hyperbranched PIs (PHBPIs) showed excellent solubility, excellent optical properties, and low birefringences in the range of 0.0022–0.0042 caused by their special hyperbranched structures and alicyclic chain segments reduced both intramolecular and intermolecular charge transfer complex effect. It also showed excellent mechanical properties with tensile modulus in the range of 1.37–1.60 GPa and good thermal stabilities. Photolithographic property of the polymer was examined by ultraviolet exposure. Scanning electron microscopic analysis revealed a highly resolved pattern with a line width of 8 μm.
      PubDate: 2014-07-14T04:44:58-07:00
      DOI: 10.1177/0954008314523055|hwp:master-id:sphip;0954008314523055
      Issue No: Vol. 26, No. 5 (2014)
       
  • Study of polymeric nanocomposite membrane made from sulfonated polysulfone
           and nanoclay for fuel cell applications
    • Authors: Prasad, M; Mohanty, S, Nayak, S. K.
      Pages: 578 - 586
      Abstract: In the present study, sulfonated polysulfone (SPSU (T)) was prepared from PSU using trimethyl silyl chlorosulfonate as a sulfonating agent. Volumetric analytic studies revealed 58% degree of sulfonation and 1.15 meq g–1 ion-exchange capacity of SPSU (T). Fourier transform infrared spectra also confirmed the occurrence of sulfonation reaction in SPSU (T). Subsequently, nanocomposite membranes were prepared by incorporating variable quantities of Cloisite 30B (C30B) within the SPSU (T) in N-methyl-2-pyrrolidone employing solution casting method. All the membranes were characterized for thermal analysis, liquid uptake, swelling behavior, and proton conductivity measurements. Thermogravimetric analysis revealed that incorporation of C30B increased the thermal stability of the membranes. Morphological study of the nanocomposite membranes was also evaluated using scanning electron microscopy and atomic force microscopy. The x-ray diffraction patterns of nanocomposite membranes confirmed exfoliation of C30B clay galleries within the SPSU (T) matrix.
      PubDate: 2014-07-14T04:44:58-07:00
      DOI: 10.1177/0954008314523458|hwp:master-id:sphip;0954008314523458
      Issue No: Vol. 26, No. 5 (2014)
       
  • Copolymer formation of 4-vinylbenzyl-9H-carbazole-9-carbodithioate and
           ethylenedioxythiophene and capacitive behavior
    • Authors: Ates, M; Uludag, N, Arican, F.
      Pages: 587 - 597
      Abstract: In this study, first, a new monomer of 4-vinylbenzyl 9H-carbazole-9-carbodithioate (VBzCzCT) was chemically synthesized and characterized using Fourier transform infrared (FTIR) reflectance, proton nuclear magnetic resonance (1H NMR), and carbon nuclear magnetic resonance (13C NMR) spectroscopies. Second, VBzCzCT and 3,4-ethylenedioxythiophene (EDOT) monomers were electrocopolymerized (VBzCzCT-co-EDOT) in 0.1 M sodium perchlorate (NaClO4)/acetonitrile (CH3CN) on glassy carbon electrode (GCE) using cyclic voltammetry (CV). Third, the best deposition conditions on the electroactivity of the modified homopolymers and copolymer were studied and characterized using different techniques such as CV, FTIR-attenuated total reflectance, scanning electron microscopy–energy dispersion x-ray analysis, and electrochemical impedance spectroscopy (EIS) analysis. The specific capacitance (C sp) of poly(VBzCzCT) (P(VBzCzCT)) was obtained as 20.5 mF cm–2. However, the C sp of P(VBzCzCT-co-EDOT)/GCE was obtained as 45.5 mF cm–2. There is an important improvement in the capacitance value of copolymer formation. The C sp value increases more than twice from P(VBzCzCT) to copolymer. The highest double layer capacitance (C dl = approximately 27.5 mF cm–2) was obtained for P(VBzCzCT-co-EDOT) and P(EDOT) compared with P(VBzCzCT) (C dl = approximately 8.28 mF cm–2. Finally, simulation graphs of Nyquist, Bode-magnitude, and Bode-phase plots were given for homopolymers and copolymer for the electrical equivalent circuit model of R s(Q 1(R 1(C 1(R 2(C 2(R 3 · W))))))(C 3 R 4). The EIS results of P(VBzCzCT), P(EDOT), and P(VBzCzCT-co-EDOT) might be studied as promising active electrode materials for (super)capacitor evaluations.
      PubDate: 2014-07-14T04:44:58-07:00
      DOI: 10.1177/0954008314523806|hwp:master-id:sphip;0954008314523806
      Issue No: Vol. 26, No. 5 (2014)
       
  • Synthesis and characterization of ternary copolyimides derived from
           aromatic dianhydride and aromatic diisocyanates
    • Authors: Guo, B; Zhang, Y, Chen, L, Yu, J, Zhu, J, Hu, Z.
      Pages: 598 - 608
      Abstract: A series of polyimide (PI) copolymers were synthesized via a one-step polycondensation procedure from benzophenone-3,3',4,4'-tetracarboxylic acid dianhydride, toluene diisocyanate (TDI), and 4,4'-methylene bis(phenyl isocyanate) (MDI) with various mole ratios of TDI and MDI ranging from 70:30 to 100:0. The inherent viscosities of the resulting PIs were in the range of 0.51–0.80 dL g–1. The prepared PIs showed good solubility in common organic as well as in less polar solvents. All copolymers afforded tough and flexible films that had good thermal stability with glass transition temperature of 308–325°C and the temperatures of 5% weight loss in air and nitrogen being 420 and 460°C, respectively. The resultant PI films with thickness about 15 μm exhibited high transparency (>88%) in visible region (400–700 nm). Also, the cured PI films possessed good mechanical properties with tensile strength of 60.52–69.31 MPa and tensile modulus of 0.98–1.30 GPa.
      PubDate: 2014-07-14T04:44:58-07:00
      DOI: 10.1177/0954008314524462|hwp:master-id:sphip;0954008314524462
      Issue No: Vol. 26, No. 5 (2014)
       
  • Nanocomposites based on thermoplastic polyurethane, millable polyurethane,
           and organoclay: effect of organoclay content
    • Authors: Barick, A. K; Chang, Y.-W.
      Pages: 609 - 617
      Abstract: Dynamically vulcanized thermoplastic polyurethane/millable polyurethane blend and its organoclay-based nanocomposites with co-agent assisted peroxide curative system were prepared by melt intercalation technique using batch mixer followed by compression molding to make sheets. Fourier transform infrared spectroscopy analysis revealed the presence of interfacial interactions due to hydrogen bonding of PUs with organoclays. X-ray diffraction and transmission electron microscopy analyses qualitatively established the uniform dispersion of organoclays within the PU matrix up to 5 phr Cloisite 30B (C30B) content and exhibited small aggregates at higher C30B loading. Mechanical testing reported significant improvement in tensile strength with addition of C30B up to 5 phr loading and then reduced a little but tensile modulus continuously increased with increase in C30B loading. Dynamic mechanical analysis (DMA) evaluated that the storage modulus (E') and glass transition temperature (T g) of both hard and soft segments of PU matrix substantially enhanced by incorporation of C30B. Thermogravimetric analysis revealed that the thermal stability of the PU matrix noticeably increased with C30B loading. Melt rheological characterization reported that all samples showed a strong shear thinning behavior within the scanned frequency range.
      PubDate: 2014-07-14T04:44:58-07:00
      DOI: 10.1177/0954008314525972|hwp:master-id:sphip;0954008314525972
      Issue No: Vol. 26, No. 5 (2014)
       
  • Mechanical and dielectric properties of blends of dicyanate ester and
           bisphenol A-based benzoxazine
    • Authors: Yan, H; Li, T, Zhang, M, Feng, S.
      Pages: 618 - 624
      Abstract: Bisphenol A-based benzoxazine (BOZ) was blended with cyanate ester (CE) to improve the properties of cyanate resin. The effects of the content of BOZ on the mechanical property and dielectric property of the blends have been investigated. The results show that a suitable addition of BOZ can enhance the impact strength and flexural strength as well as reduce the dielectric constant and the dielectric loss of CE. The mechanical properties are significantly improved when the content of BOZ is 10 wt%, and the dynamic mechanical analysis reveals that the cross-link density of the blend is lower than pure CE. Scanning electron microscopy analysis shows distinct characteristics of ductile fracture of the blends. In addition, the dielectric constant and the dielectric loss of modified system decreases, compared with the curing CE. The optimal addition amount of BOZ resin is 15 wt% for the dielectric properties. The blend of a suitable addition of BOZ still remains a good thermal resistance. All these changes in properties are closely correlated to the copolymerization between BOZ and CE.
      PubDate: 2014-07-14T04:44:58-07:00
      DOI: 10.1177/0954008314526423|hwp:master-id:sphip;0954008314526423
      Issue No: Vol. 26, No. 5 (2014)
       
 
 
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