Synthesis of copolymer grafts containing sulfoalkyl and hydrophilic groups in polymer electrolyte membranes

▸ PEM having sulfoalkyl and hydroxyl groups were prepared by radiation-grafting. ▸ Membrane showed a conductivity of 3.8×10−3 S cm−1 under 30% RH at 80 °C. ▸ Hydroxyl groups in sulfoalkyl grafts affect proton mobility even at low RH. ▸ Mechanical properties of the membrane are better than those of Nafion.