writer：J. Wang*, Y. Song, C. Zhang, Z. Ye, H. Liu, M.-H. Lee, D. Wang, J. Ji
keywords：FT-IR, NMR, Polybenzimidazoles, Poly(arylene ether ketone)s, Proton exchange membranes
source：期刊
specific source：Macromolecular Chemistry and Physics
Issue time：2008年

A novel alternating copolymer of sulfonated poly(ether ether ketone-benzimidazole)s (SPEEK-BI) was synthesized by polycondensation of aromatic bisphenol containing benzimidazole and a mixture of sulfonated and non-sulfonated difluorobenzophenones. By varying the amount of two difluorobenzophenones, the ratio of sulfonic acid unit to imidazole base was controlled straightforwardly. The polymer structure was characterized by ¹H NMR and IR spectroscopy. Two different methods of ion exchange capacity measurement supported a strong inter- and intra-molecular interaction between acid and base units, which resulted in an improved mechanical strength as well as avoiding phase separation. Tough membranes with good mechanical stability in hot water (80 8C) and alcohol were obtained by solution casting, which is potential for applications in polymer electrolyte membrane fuel cells and membranes for separation of liquids or gases.