改性聚苯乙烯磺酸质子交换膜材料的制备及机理

The Study on the Manufacture and Machinery of Modified Sulphonated Polystyrene Membrane

为了将价廉易得的聚苯乙烯磺酸类材料重新用作先进燃料电池的质子交换膜,以便大大地降低质子交换膜燃料电池的成本,文章采用模型化合物、C13核磁共振谱、饱和铁氰化钾溶液等进行化学稳定性实验,做成实验电池进行恒电流充放电循环,以及以铂黑(Pt)为电催化剂制备膜电极组件并组装单体电池进行测试等方法对含叔碳氢原子的聚苯乙烯磺酸聚合物与不含叔碳氢原子的聚a-甲基苯乙烯磺酸聚合物进行了对比研究。研究结果表明,对比经老化处理前后的模型化合物对异丙基苯磺酸与对叔丁基苯磺酸的C13核磁共振图谱,前者在羧基与酯基的特征区(169×10-6～180 ×10-6)、羟基碳或醚基碳的特征区(50×10-6～80×10-6)及直链碳的特征区(15×10-6～35×10-6)都有强吸收峰,而后者却仅在170 ×10-6处有弱吸收峰;聚苯乙烯磺酸膜浸泡在饱和铁氰化钾溶液8天后的质量损失高达20%,而聚a-甲基苯乙烯磺酸膜的质量损失仅为7.0%左右;以聚苯乙烯磺酸膜为隔膜的实验电池经过恒电流充放电循环120次后的电池容量不到初始容量的50%,电池已失效,而以聚a-甲基苯乙烯磺酸膜为隔膜的实验电池在经过120次恒电流充放电循环后的电池容量为初始容量的84%,且经过300次循环后的容量仍维持在初始容量的70%以上;以铂黑(Pt)为电催化剂,聚a-甲基苯乙烯磺酸膜?

The effect of tertiary hydrogen on the chemical stability of polymer was studied. The tertiary hydrogen, which exists in the microstructure, really has responsible for poor oxidability abilities of sulphonated polystyrene membranes. The performances were studied and compored between a -methyl sulphonated polystyrene and sulphonated polystyrene by methods of model compounds , C13 NMR , etc. The conclusions were drawn as the following: ①Compared spectrums of model compounds,there were strong resonances in the ranges of 169×10-6-180×10-6,50×10-6-80×10-6 and 15×10-6-35×10-6 in spectrum of sulfonated isopropylbenzene after being aged for 8 days;②Sulphonated polystyrene membranes exhibited more weight loss(20%) during exposurd to an oxidizing aging solution than poly a-methylstyrene membranes(7.0%);③The energy efficiencies of experimental cell used sulphonated polystyrene membrane decreased rapidly to less than 50% after 120 cycles in a cycling test and sulphonated poly|á-methylstyrene membrane 70% after 320 cycles.And this article also supported a new method to modified polystyrene membranes.