Novel iodo-containing poly(arylene ether ketone)s as intermediates for grafting perfluoroalkyl sulfonic acid groups

A synthetic approach to poly(arylene ether ketones) grafted with super-acidic perfluoroalkyl-sulfonic-acids is reported. A series of iodo-containing poly(arylene ether ketone)s derived from a 4-iodophenylated hydroquinone monomer were synthesized by aromatic nucleophilic substitution (SNAr). The iodo-containing polymers were functionalized via the Ullmann reaction to give poly(arylene ether ketone)s grafted with perfluoroalkyl-sulfonic-acid. The perfluoroalkyl-sulfonic-acid functionalized aromatic polymers were investigated as proton exchange membranes (PEM). The membranes had good overall properties of thermal-oxidative stability, mechanical strength, methanol permeability and proton conductivity. A membrane with IEC ~ 1.37 meq g− 1 had a proton conductivity of 0.088 S cm− 1 at 100 °C, which was higher than many sulfonated hydrocarbon PEMs with similar IEC values.