1. College of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou, 310014, China;2. School of Engineering, Laurentian University, Sudbury, Ontario, Canada P3E 2C6;3. Department of Polymer/Nano Science and Technology, Chonbuk National University, 664‐1, Dukjin, Chonju, Chonbuk 561‐756, Korea
Abstract:
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 °C) 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.
