Structure-property correlations of sulfonated polyimides. I. Effect of bridging groups on membrane properties

摘要: A series of sulfonated polyimides with increasing alkyl substituents in the o-position to diamine were synthesized from 4,4′-methylene dianiline, 4,4′-diamine-3,3′-dimethyl-diphenylmethane, and 4,4′-diamine-3,5,3′,5′-tetraethyl-diphenylmethane using 1,4,5,8-naphthalenetetracarboxylic dianhydride perylenetetracarboxylic by chemical imidization method. 4,4′-Diaminobiphenyl 2,2′-disulfonic acid was used as diamine. The variation membrane properties increase substitution analyzed. Solubility increased whereas thermal stability decreased substitution. Ion exchange capacity water uptake reduced because low sulfonic content at a particular weight due molecular repeating unit. conductivity substituted diamines higher than unsubstituted temperature regardless ion uptake. more rapid Nafion®115. Hydrolytic is diamines. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Chem 42: 3621–3630,