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91.
Sulphonated polystyrene ethylene butylene polystyrene(SPSEBS)prepared with 35%sulphonation was found to be highly elastic and enlarged up to 300%-400%of its initial length.It absorbed over 110%of water by weight.A major drawback of this membrane is its poor mechanical properties which are not adequate for use as polymer electrolytes in fuel cells.To overcome this,SPSEBS was blended with poly(vinylidene fluoride)(PVDF),a hydrophobic polymer.The blend membranes showed better mechanical properties than the base polymer.The effect of PVDF content on water uptake,ion exchange capacity and proton conductivity of the blend membranes was investigated.This paper presents the results of recent studies applied to develop an optimized in-house membrane electrode assembly(MEA)preparation technique combining catalyst ink spraying and assembly hot pressing.Easy steps were chosen in this preparation technique in order to simplify the method,aiming at cost reduction.The open circuit voltage for the cell with SPSEBS is 0.980 V which is higher compared to that of the cell with Nafion 117(0.790 V).From this study,it is concluded that a polymer electrolyte membrane suitable for proton exchange membrane fuel cell(PEMFC)and direct methanol fuel cell(DMFC)application can be obtained by blending SPSEBS and PVDF in appropriate proportions.The methanol permeability and selectivity showed a strong influence on DMFC performance. 相似文献
92.
A tetrafunctional epoxy monomer, N,N,N′-N′-tetraglycidyl-4,4′-diaminodiphenyl methane (TGDDM), has demonstrated to be a highly efficient reactive compatibilizer in compatibilizing the immiscible and incompatible polymer blends of polyamide-6 (PA6) and poly(2,6-dimethyl-1,4-phenylene ether) (PPE). This epoxy coupler can react with both PA6 and PPE to form various PA6-co-TGDDM-co-PPE mixed copolymers. These interfacially formed PA6-co-TGDDM-co-PPE copolymers tend to anchor along the interface to reduce the interfacial tension and result in finer phase domains and enhanced interfacial adhesion. A simple one-step melt blending has demonstrated to be more efficient in producing a better compatibilized PA6/PPE blend than a two-step sequential blending. The mechanical property improvement of the compatibilized blend over the uncompatibilized counterpart is very drastic, by considering the addition of a very small amount, a few fractions of 1%, of this epoxy coupling agent. © 1998 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 36: 1805–1819, 1998 相似文献
93.
Processable polyaniline doped and complexed with dodecylbenzenesulfonic acid was obtained by one-step micellar chemical polymerization of aniline in the presence of dodecylbenzenesulfonic acid. Homogeneous transparent suspension could be made by dispersing processable polyaniline in m-cresol without any precipitation. Polyaniline composite film blended with polymethylmethacrylate (PMMA) exhibits relatively high levels of conductivity at low volume fractions of the polyaniline, while keeping good mechanical properties, equivalent to those of the PMMA. © 1998 John Wiley & Sons, Ltd. 相似文献
94.
聚丙烯共混物反应挤出过程中的降解抑制 总被引:4,自引:0,他引:4
聚丙烯/(丙烯腈-苯乙烯)共聚物在过氧化二异丙苯存在下反应共混挤出时,加入亚油酸三甘酯可以有效地抑制过程的降解,从挤出物中分离出聚丙烯组分测试熔体流动速率表明,加入亚油酸三甘酯后,其熔体流动速率有很大下降,扫描电子显微镜的观察表明,调节过氧化二异丙苯和亚油酸三甘酯的加入量,可有效控制降解并生成较多的接枝物相容性,显著改善相形态。 相似文献
95.
辐射增强PP/BR共混体系的力学性能 总被引:5,自引:0,他引:5
研究了在多官能团单体-三烯丙基异氰酸酯存在下,共混体系聚丙烯/1.4-聚丁二烯橡胶的辐射效应,用DSC,动态粘弹谱对其进行表征。结果显示,三烯丙基异氰酸酯主要分布于聚丙烯/1.4-聚丁二烯橡胶共混物的界面自高能射线作用下,被引发参与界面反应,从而改善了共混体系的相容性,增强也界面粘接,提高了共混物的力学性能。 相似文献
96.
97.
Inrecentyears,thenewsedricrystallinepolymersyndiotacticp0lystyrene(sPS)hasat-ITactedmuchattentionduetoitsg0odchendcalresistanceandenhancedmechanicalperformanceatelevatedtemPeratUre.'H0wever,itexhibitshighbrittlenessandpoorimPact-resistanceandtCar-resistance.2Therefore,itisnecessarytomodifyitwithtougheningpolyIners.AsimPlemeth0dto0verc0methedriscibilityofatwo-phaseblendofsPSandatougheningpolymristotwrovetheinterfacialaffmity,wheretheadditionofablockcoP0lymerisconsideredtobemosteffective.3… 相似文献
98.
99.
Yong He Naoki Asakawa Yoshio Inoue 《Journal of Polymer Science.Polymer Physics》2000,38(14):1848-1859
The effects of several low molecular weight compounds with hydroxyl groups on the physical properties of poly(ε‐caprolactone) (PCL) were investigated by Fourier transform infrared (FTIR) spectroscopy and high‐resolution solid‐state 13C NMR. PCL and 4,4′‐thiodiphenol (TDP) interact through strong intermolecular hydrogen bonds and form hydrogen‐bonded networks in the blends at an appropriate TDP content. The thermal and dynamic mechanical properties of PCL/TDP blends were investigated by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis, respectively. The melting point of PCL decreased, whereas both the glass‐transition temperature and the loss tangent tan δ of the blend increased with an increase in TDP content. The addition of 40 wt % TDP changed PCL from a semicrystalline polymer in the pure state to a fully amorphous elastomer. The molecules of TDP lost their crystallizability in the blends with TDP contents not greater than 40 wt %. In addition to TDP, three other PCL blend systems with low molecular weight additives containing two hydroxyl groups, 1,4‐dihydroxybenzene, 1,4‐di‐(2‐hydroxyethoxy) benzene, and 1,6‐hexanediol, were also investigated with FTIR and DSC, and the effects of the chemical structure of the additives on the morphology and thermal properties are discussed. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 38: 1848–1859, 2000 相似文献
100.
The effects of host/filler interactions, processing, and morphological development of low percolation threshold (Φc) conducting blends were investigated. It was found that the value of Φc was dramatically reduced by the isolation of the carbon black (CB) conducting filler at the cocontinuous interface of a binary poly(styrene) (PS) and poly(styrene co‐acrylonitrile) (SAN) insulating host, resulting in a multiple percolation effect. Accumulation of the filler at the interface was possible due to the incompatibility of the CB filler with the PS phase and partial compatibility with the SAN phase. The best results were obtained by initially dispersing the CB in the PS phase during melt‐ blending, followed by the addition of the SAN phase. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 38: 3106–3119, 2000 相似文献