Influence of the polymer backbone structure on the properties of aromatic ionomers with pendant sulfobenzoyl side chains for use as proton-exchange membranes
Six different ionomers having various aromatic polymer backbones with pendant 2-sulfobenzoyl side chains were prepared by nucleophilic aromatic substitution reactions of lithium 2,6-difluoro-2′-sulfobenzophenone with 4,4-biphenol, 2,7-dihydroxynaphthalene, 4,4-isopropylidenediphenol, 4,4-dihydroxydiphenyl ether, 4,4′-thiodiphenol, and 4,4′-thiobisbenzenethiol, respectively, to produce four poly(ar