Preparation and characterization of sulfonated semi-crystalline poly(arylene ether)s containing 1,4-FBB moiety as proton exchange membrane fuel cells

Abstract

Sulfonated semi-crystalline poly(arylene ether)s copolymers containing 1,4-bis(4-fluorobenzoyl)benzene (1,4-FBB), with different degrees of sulfonation (DS), were successfully synthesized via direct polycondensation of 3,3’-disulfonate-4,4’-difluorodiphenylsulfone, bisphenol A, and 1,4-bis(4-fluorobenzoyl)benzene, based on aromatic nucleophilic substitution. The different DS values were realized by controlling the quantity of the sulfonated monomer. The effects of DS on the thermal, mechanical, and oxidative stabilities, water uptake, and ion exchange capacity of the membranes were determined. Compared with Nafion 212®, a state-of-the-art proton-conducting membrane, the block copolymer membrane showed well-separated phase morphology and high proton conductivity at different temperatures. The chemical and phase-separated structures of the copolymers were characterized by proton nuclear magnetic resonance spectroscopy and atomic force microscopy studies. The results showed that semi-crystalline copolymer membranes had acceptable mechanical, thermal, electrochemical, and chemical stabilities. All the above-mentioned results indicate that these semi-crystalline copolymer membranes are good candidate materials for proton exchange membranes.