Synthesis and properties of a novel poly(aryl ether ketone)s with quaternary ammonium pendant groups for anion exchange membranes

The poly(aryl ether ketone)s containing two quaternary ammonium groups on pendant phenyls are obtained via a bromination reaction following a quaternization process. Poly(aryl ether ketone)s with two methyl groups on pendant phenyls, which can be converted to bromomethyl groups by a radical reaction, are synthesized. Cationic quaternized poly(aryl ether ketone)s result from conversion of the bromomethyl groups to ionic moieties by quaternization with trimethylamine in the shape of clear, creasable films. The highest conductivity 0.0307 S cm−1 is achieved by the QMPAEK-75 membrane with ion exchange capacity of 1.35 meq. g−1 at 80 °C. Meanwhile, these anion exchange membranes also have good mechanical properties, very low methanol permeability, high thermal stability, chemical stability and dimensional stability, which play important roles in the preparation of direct methanol fuel cells.