Direct synthesis of sulfonated poly(phthalazinone ether) for proton exchange membrane via N–C coupling reaction

Sulfonated poly(phthalazinone ether)s 7a–f were directly synthesized by aromatic nucleophilic polycondensation of bisphthalazinone 4 with the mixture of sulfonated dihalide 5 and non-modified dihalide 6 via N–C coupling reaction. The sulfonated polymers were characterized by 1H NMR, elemental analysis and other technologies. Because of their specially designed molecular structure, the novel sulfonated polymers showed excellent thermal and oxidative stability. The sulfonated polymers also had reasonable water affinity and moderate proton conductivity for the usage in proton exchange membrane fuel cells.