共查询到18条相似文献,搜索用时 156 毫秒
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以2.0 dtex、51mm的聚苯硫醚(PPS)纤维为原料,以双氧水为氧化剂、冰乙酸为催化剂,对PPS纤维进行氧化改性处理,通过改变氧化反应温度和反应时间等工艺条件,制备聚苯硫醚砜(PPSO)纤维和聚芳砜(PASO)纤维,并对改性纤维的结构形貌及性能进行表征。结果表明:在双氧水:蒸馏水:冰乙酸质量比为50:25:25、氧化反应时间为5 h的条件下,当氧化反应温度为25~60℃时得到PPSO纤维,当氧化反应温度升高至80℃时得到PASO纤维;氧化改性过程中,伴随着硫(S)原子流失和聚芳烃的生成,改性纤维中出现大量氧(O)元素,证明PPS纤维被成功氧化改性;氧化处理对纤维的表面形貌影响不大,但纤维力学性能降低;经硝酸溶液浸泡处理后,PPS纤维强度保持率为79.8%,而PASO纤维强度保持率提高到112.2%, PPSO纤维强度保持率高达138.1%,说明氧化改性后的PPS纤维抗氧化能力明显提高。 相似文献
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在以前工作的基础上优化反应体系和工艺流程,通过放大和稳定性试验在常压下合成高分子量的聚苯硫醚砜(PPSSU),为PPSSU复合材料的制造打下了基础。同时初步探索了PPSSu/玻璃纤维布复合材料的制备方法与工艺条件,并对产品的结构与性能进行了表征。结果显示,该材料比聚苯硫醚更适于在高温下使用,其弯曲强度在180℃时仍然可保持其室温强度的70%。 相似文献
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在以前工作的基础上优化反应体系和工艺流程,通过放大和稳定性试验在常压下合成高分子量的聚苯硫醚砜(PPSSU),为PPSSU复合材料的制造打下了基础。同时初步探索了PPSSU/玻璃纤维布复合材料的制备方法与工艺条件,并对产品的结构与性能进行了表征。结果显示,该材料比聚苯硫醚更适于在高温下使用,其弯曲强度在180℃时仍然可保持其室温强度的70%。 相似文献
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采用相转化法制备了磺化聚砜(SPSF)/聚醚砜(PES)共混新型纳滤膜,并研究了SPSF/PES共混质量比、水解的苯乙烯–马来酸酐共聚物(H–PSMA)的添加量、铸膜液预蒸发时间和温度对膜的脱盐率及水通量的影响。结果表明,当SPSF/PES共混质量比为4∶6,添加剂H–PSMA的质量分数为2%,铸膜液预蒸发时间为3 min,预蒸发温度为70℃时,在操作压力为0.5 MPa,料液温度为25℃下,SPSF/PES共混膜对2 g/L的Na_2SO_4盐溶液脱盐率为56.77%,水通量为24.45 L/(m~2·h)。 相似文献
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采用电镜和孔径分布测定仪对自制聚醚砜( PES)和磺化聚醚砜(SPES)膜进行表征,根据Darcy-Poiseuille定律研究PES膜和SPES膜过滤牛血清蛋白液(BSA)阻力分布情况.结果表明,PES膜孔径为0.22~0.27 μm,初始纯水通量为642 L·m-2·h-1,过滤质量浓度为1 g·L-1的BSA溶液时平衡通量为30.4~31.9 L·m-2· h-1; SPES膜孔径为5.2~11.1 nm,初始纯水通量为8.1 L·m-2·h-1,质量浓度为1 g·L-1的BSA时平衡通量为3.4~6.9 L· m-2·h-1.过滤时PES膜阻力主要集中在吸附和堵孔阻力,2者相加为总阻力的91.1%;而SPES膜阻力主要集中在膜本身的阻力,为总阻力的41.8%,其次为堵孔阻力,占总阻力的38.3%.经清洗后,PES膜的纯水通量可以恢复到82%,而SPES膜可以恢复到494%. 相似文献
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聚亚苯基砜的合成与表征 总被引:1,自引:0,他引:1
以环丁砜为溶剂,用4,4'-二氯二苯砜和4,4'-联苯二酚为单体,无水碳酸钾为成盐剂,甲苯为脱水剂,采用"成盐"和"缩聚"两步反应合成出了我国长期依赖进口的特种工程塑料聚亚苯基砜(PPSU),并对产物进行了纯化。对比分析和测试了自制样品和美国Solvay公司产的PPSU样品的比浓对数黏度,C、H和K元素含量,核磁共振氢谱,傅里叶变换红外光谱,激光拉曼光谱,玻璃化转变温度和热分解温度。结果表明它们具有相同的化学结构、相近的分子量和纯度,自制PPSU的玻璃化转变温度比Solvay公司产的高约5℃,热稳定性相差不大。 相似文献
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Md. M. Islam H.‐H. Jang Y.‐D. Lim D.‐W. Seo T.‐H. Kim Y.‐T. Hong D.‐M. Kim W.‐G. Kim 《Fuel Cells》2012,12(6):978-986
Sulfonated cardo poly(arylene ether sulfone)s ( SPPA ‐ PES ) with various degrees of sulfonation (DS) were prepared by post‐sulfonation of synthesized phenolphthalein anilide ( PPA ; N‐phenyl‐3,3′‐bis(4‐hydroxyphenyl)‐1‐isobenzopyrolidone) poly(arylene ether sulfone)s ( PPA ‐ PES ) by using concentrated sulfuric acid. PPA ‐ PES copolymers were synthesized by direct polycondensation of PPA with bis‐(4‐fluorophenyl)‐sulfone and 4,4′‐sulfonyldiphenol. The DS was varied with different mole ratios of PPA (24, 30, 40, 50 mol.%) in the polymer. The structure of the resulting SPPA ‐ PES copolymers and the different contents of the sulfonated unit were studied by Fourier transform infrared (FT‐IR) spectroscopy, 1H NMR spectroscopy, and thermogravimetric analysis (TGA). Sorption experiments were conducted to observe the interaction of sulfonated polymer with water. The ion exchange capacity (IEC) and proton conductivity of SPPA ‐ PES were evaluated according to the increase of DS. The water uptake (WU) of the resulting SPPA ‐ PES membranes was in the range of 20–72%, compared with 28% for Nafion 211®. The SPPA ‐ PES membranes showed proton conductivities of 23–82 mS cm–1, compared with 194 mS cm–1 for Nafion 211®, under 100% relative humidity (RH) at 80 °C. 相似文献
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Blend membranes based on high conductive sulfonated poly(1,4‐phenylene ether‐ether‐sulfone) (SPEES) and poly(vinylidene fluoride) (PVDF) having excellent chemical stability were prepared and characterized for direct methanol fuel cells. The effects of PVDF content on the proton conductivity, water uptake, and chemical stability of SPEES/PVDF blend membranes were investigated. The morphology, miscibility, thermal, and mechanical properties of blend membranes were also studied by means of scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA) measurements. The blend membrane containing 90 wt.% SPEES (degree of sulfonation – DS = 72%) and 10 wt.% PVDF (Mw = 180,000) exhibits optimum properties among various SPEES72/PVDF membranes. Addition of PVDF enhanced resistance of the SPEES membrane against peroxide radicals and methanol significantly without deterioration of its proton conductivity. It's proton conductivity at 80 °C and 100% relative humidity is higher than Nafion 115 while it's methanol permeability is only half of that of Nafion 115 at 80 °C. The direct methanol fuel cell performance of the SPEES membranes was better than that of Nafion 115 membrane at 80 °C. 相似文献
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聚(2,5—二甲基)对苯硫醚合成的初步研究 总被引:2,自引:1,他引:1
介绍以硫磺、氯和对二甲苯为原料,无水三氯化铁(FeCl3)作催化剂,三氯甲烷(CH3Cl3)作溶剂,合成聚(2,5-二甲基)对苯硫醚(DMPPS)。最佳反应条件为:最佳投料摩尔比:对二甲苯/SCl2/FeCl3=1.0/1.02/0.10,反应温度20~80℃,反应时间5~6h。收率为62.5%。产品经红外光谱、X射线衍射光谱、激光拉曼光谱和差热分析验证,为线型结晶性,无双硫键,熔点Tm为306℃(美国RytonV-1型PPS熔点为275~285℃的工程高聚物。所述合成方法原料和催化剂价廉易得、合成工艺简化、无副产物NaCl产生、操作易、周期短、成本比PPS低。其不足之处是产品收率不够高,有待在溶剂和催化剂选择方面作进一步研究。 相似文献