One-pot acylation/benzimidazolization copolymerization approach to side-chain-type proton conductive membranes

Novel ‘one-pot acylation/heterocyclization copolycondensation’ approach bearing the merit of orthogonal tuning of the contents of both sulfonate groups and heterocyclic rings has been proposed for the first time and proved by the successful synthesis of side-chain-type sulfonated poly(ether ketone/ether benzimidazole) containing side-chain sulfonate groups and main-chain benzimidazole rings at a molar ratio of 9/1 via acylation of sulfonated monomers and benzimidazolization simultaneously in a one-pot way. The corresponding membrane exhibited proton conductivity as high as 55 mS cm−1 at 30 °C, much higher than those of conventional sulfonated benzimidazole-containing polymers, showing great promise for application in PEMFCs.