自交联型季铵化聚醚砜阴离子交换膜的制备与性能

Preparation and Properties of Anion Exchange Membranes Based on Self-crosslinked Quaternary Ammonium Poly(ether sulfone) s

为改善聚醚砜类阴离子交换膜(QPES)的离子电导率及稳定性,采用3种具有不同长度的脂肪族二胺,即N,N,N',N'-四甲基乙二胺(TMEDA)、N,N,N',N'-四甲基丙二胺(TMPDA)及N,N,N',N'-四甲基己二胺(TMHDA),通过溶液浇铸法制备了一系列自交联型季铵化聚醚砜阴离子交换膜(CQPES).交联膜的抗溶剂性能显著增强,在膜面方向的尺寸稳定性、机械性能、耐水解稳定性及耐碱稳定性均得到了提高,同时离子电导率保持在较高的水平.CQPES膜的性能与二叔胺的结构有较大的关系,以TMHDA为交联剂的CQPES膜离子电导率、耐水解稳定性及耐碱稳定性优于以TMEDA及TMPDA为交联剂的体系.如IEC为1.45 mmol/g的CQPES-H-0.5膜,在30℃时吸水率为43%,尺寸变化率小于10%;在30℃及60℃的水中的电导率分别达到17 m S/cm及64 m S/cm.在稳定性测试方面,CQPES-H-0.5膜经过100℃水处理24 h后重量损失为3.8%,4 mol/L的Na OH溶液室温处理168 h后,离子电导率损失为21%;而相同条件下非交联处理的QPES膜分别为12%及40%.CQPES-H-0.5膜显示了良好的性能,有望在燃料电池系统中得到应用.

In order to improve the ion conductivity and alkaline stability of the anion exchange membranes derived from quaternary ammonium poly（ether sulfone）s, a series of new self-crosslinked membranes （CQPES） were successfully prepared from three kinds of aliphatic di-tertiary amines, namely, N,N, N＇,N＇- tetramethylethylenediamine （ TMEDA）, N, N, N＇, N＇-tetramethyl-1,3-propanediamine （TMPDA） and N, N, N＇, N＇- tetramethyl-1,6-hexanediamine （TMHDA） , by solution casting. For the CQPES membranes, their properties such as solvent resistance, dimensional stability, mechanical stability, hydrolytic stability as well as alkaline stability were enhanced significantly, while the high ion conductivity was maintained. For example, the membrane of CQPES-H-0.5 （ 1.45 mmol/g,TMHDA as the cross-linker） showed 43% of water uptake,lower than 10% of size change in in-plane direction at 30 ~C , and 17 mS/era and 64 mS/era of ionic conductivity in water at 30 ℃ and 90 ℃ ,respectively. During the evaluation of stability,21% loss in ionic conductivity after treatment in 4 mol/L NaOH solution for 168 h and 3.8% loss in weight after treatment in 100 ℃ water for 24 h were found for CQPES-H-0.5 membrane, while 12% and 40% losses were for the uncrosslinked membrane （QPES） , respectively. The excellent performance of CQPES-H-0.5 suggests its potential application in the fuel cell system.