含砜基磺化聚酰亚胺的合成及其质子导电率和耐水性

Synthesis,Proton Conductivity and Water Stability of Sulfonated Polyimides from a New Sulfonated Sulfonyl-containing Diamine Monomer

合成了一种新型的含有砜基的磺化二胺单体4,4’-二(4-氨基苯氧基)二苯砜-3,3’-二磺酸(BAPPSDS)以及相应的具有不同离子交换容量(IEC)的磺化聚酰亚胺.所制得的聚合物具有良好的溶解性、成膜性及很高的热稳定性,在高相对湿度下及水中这些磺化聚酰亚胺膜显示出较高的质子导电率(与Nafion 117相当).膜的耐水性与其IEC值及磺化二胺单体的构型有关,降低膜的IEC值和使用线型磺化二胺单体可以极大地提高膜的耐水性.得到了既具有较高的质子导电率又有良好耐水性的磺化聚酰亚胺膜.

A novel sulfonated diamine monomer, 4,4＇-bis（4-aminophenoxy） diphenyl sulfone-3,3 ＇-disulfonic acid （BAPPSDS）, was synthesized via two-step reactions. A series of sulfonated （co）polyimides with controlled ion exchange capacities （IECs） were prepared from 1,4,5,8-naphthalenetetracarboxylic dianhydride （NTDA）, BAPPSDS, and common nonsulfonated diamines in m-cresol in the presence of triethylamine and benzoic acid at 180℃. The resulting sulfonated copolyimides show good solubility and high thermal stability. At high relative humidities the sulfonated copolyimide membranes exhibit high proton conductivities which are comparable to that of Nation 117. The water stability is strongly dependent on both the IEC level and the configuration of the sulfonated diamine. Polyimide membranes with high proton conductivity as well as good water stability were developed.