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制备了一系列离子交换容量不同的全氟磺酸树脂(PFSR),采用熔融流延工艺将其制备成膜。通过对不同的PF-SR进行红外光谱表征发现在1147,984cm-1处谱峰相对强度的差异反映了聚合物离子交换容量的不同。采用毛细管流变仪测试了PFSR的表观黏度、非牛顿指数、黏流活化能等流变参数,讨论了剪切速率、温度、离子交换容量对PFSR熔体的表观黏度及非牛顿指数的影响和黏流活化能随剪切速率的变化规律。结果表明,PFSR熔体的表现黏度随剪切速率、温度、离子交换容量的升高而降低;在试验温度范围内,熔体的非牛顿指数小于1,属于假塑性流体;黏流活化能随剪切速率及离子交换容量的增大而明显减小。 相似文献
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选取3种不同的离子交换容量(IEC)的氟型全氟磺酸离子交换树脂(PFSR),采用熔融流延挤出方法来制备不同IEC值的离子交换薄膜.分别利用热失重分析(TGA)、熔体流动速率仪、毛细管流变仪、哈克扭矩流变仪、X射线衍射(XRD)对3种树脂的熔融加工稳定性、熔体流变性能及挤出树脂的结晶性能进行了全面的分析研究.结果表明,在380℃以下,3种树脂的静态稳定性都很好,但当温度升高,静态稳定性随树脂IEC的升高而下降.低剪切速率下,PFSR熔融温度随IEC的升高而明显降低.PFSR树脂为剪切变稀型非牛顿流体,其表观黏度对加工剪切速率敏感;PFSR树脂在高剪切速率下的动态热稳定性能明显下降,当达到240℃以上,树脂中会出现微小气泡,其加工和动态热稳定温度随IEC值的降低而增加.另外,PFSR树脂为一种低结晶型聚合物,其结晶能力主要受其IEC值影响,并随其增加而下降. 相似文献
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全氟磺酰树脂具有优异的机械强度、化学和电化学稳定性。文中详述了影响全氟磺酸树脂质子交换膜性能的主要因素、制备工艺及其替代物质,同时阐述了作为催化剂在有机合成、药物合成方面的应用。最后探讨了全氟磺酰树脂在各领域的综合应用,以提高回收利用率,降低成本。 相似文献
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采用溶胶-凝胶法制备了用于甲醇气相脱水制二甲醚的新型催化剂全氟磺酸树脂/二氧化硅,应用X射线衍射、红外光谱、热重-差示扫描量热、低温氮物理吸附和氨程序升温脱附法对所得催化剂进行了表征。考察了反应温度、甲醇液空速、全氟磺酸树脂含量对甲醇气相催化脱水制二甲醚反应性能和催化剂稳定性的影响。结果表明,催化剂比表面积达820m2/g,在全氟磺酸树脂负载量10.0%、甲醇液空速1h?1、反应温度184℃时,甲醇转化率92.0%,二甲醚选择性99.9%,经350h实验测试,活性和稳定性没有明显变化。 相似文献
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Nonmodified and corona‐activated conifer wood flour was evaluated as filler to nitrile butadiene rubber (NBR) compounds containing different amounts of phenol‐formaldehyde resin (PFAR) by studying the cure characteristics and the mechanical properties of the filled compounds. It was found that the PFAR affects considerably the cure characteristics and the mechanical properties of the wood flour–filled NBR compounds due to a presumable action as an interface interactions modifier. Acting as an antiaging agent it improves also their thermal‐oxidative stability. The optimal amount of PFAR regarding the cure characteristics and mechanical parameters is of 15 phr/100 phr wood flour. The addition of PFAR just before the wood flour is preferable because of both its better homogenization in the rubber matrix and its lower adsorption by the wood flour, leading to an improvement of the mechanical properties of the wood flour–filled NBR compounds. The replacement of nonmodified wood flour by corona‐activated wood flour leads to additional increase of the mechanical parameters without significant affect of the optimum cure time, aging resistance, and water adsorption. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 95–101, 2004 相似文献
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RTM专用混合型树脂体系研究——反应特性与工艺特性研究 总被引:10,自引:4,他引:6
本文采用乙烯基酯树脂和环氧树脂体系共混改性的方法。研究和开发具有良好工艺性、耐热性和力学性能的低成本RTM用树脂体系。研究表明,乙烯基酯树脂和环氧树脂体系具有良好的共混特性。DSC及粘度分析研究表明,混合型树脂体系中的乙烯基酯组份分散了环氧树脂的反应放热,有效降低了711环氧树脂的反应速度和改善了树脂的工艺特性。使混合型树脂具有较好的RTM工艺低粘度平台工艺性能。所研究的混合型树脂体系可用于RTM 相似文献
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《国际聚合物材料杂志》2012,61(1):25-32
Castor oil (CO) was reacted with commercial epoxy resin (ER) (diglycidylether of bisphenol-A, DGEBA) at various mole ratios. The resultant products were designated as COERs and characterized by physical, chemical and IR spectral studies. A commercial alkyd resin was blended with various proportions of COERs and ketone resin (i.e., cyclohexanone-formaldehyde resin) (CHF). All the blends were applied on mild steel panels and characterized for drying time, adhesion, flexibility, hardness, impact resistance and chemical resistance properties. 相似文献
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Dipak K. Raval Amit J. Patel Bhavil N. Narola 《Polymer-Plastics Technology and Engineering》2013,52(3):293-299
Amino resins are used for various applications such as decorative plastic plates, decorative wood boards, particle boards, leather tanning, foam, coating, and molding materials. In the present work, it was planned to prepare modified melamine-formaldehyde resin by incorporating casein. The intended melamine-formaldehyde-casein (MFC) resin samples were prepared under alkaline condition with an 1:3 melamine: formaldehyde ratio. Casein was incorporated in varying proportions (up to 25% w/w of melamine content) at 85–90°C. The samples were characterized by viscosity measurement and vapor pressure osmometry (VPO). The resin samples were cured isothermally at 60°C using ammonium chloride as well as hydroxylamine hydrochloride and at 120°C using hexamine as the curing agents. Jute fabric (JFRC) and glass fabric reinforced composites (GFRC) were produced by maintaining 60:40 and 40:60 proportion of resin to reinforcement materials, respectively. The laminates thus formed were characterized for their mechanical properties and chemical resistance. 相似文献
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环氧树脂的合成与应用研究概况 总被引:1,自引:0,他引:1
环氧树脂因具有优良的物理机械性能、化学稳定性、耐化学腐蚀性、耐热及粘接性能而得到广泛应用.其种类繁多且合成方法各异.文章以双酚A型环氧树脂为例对环氧树脂合成工艺及其在不同领域的几种应用形式分别进行了综述. 相似文献
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