A novel proton exchange membrane derived from trisulfonated poly(arylene ether phosphine oxide) containing diphenyl ether moieties

A series of novel trisulfonated phosphine oxide polymers (tsPEPO-x) with different sulfonation degrees were prepared by intermolecular polymerization of trisulfonated phosphine monomer and 4,4(')-dihydroxydiphenyl ether. The properties of these membranes were investigated in detail. The results showed that these membranes, especially those with high sulfonation degree, exhibited excellent overall performance. For example, the conductivity of tsPEPO-120 membrane reaches 0.093 S cm(-1) at 80 degrees C, which is higher than that (0.087 S cm(-1)) of Nafion 117. At the same time, the swelling rate is almost equivalent to that (20%) of Nafion 117. Moreover, the membrane also has good oxidation resistance in Fenton's reagent. The obtained polymers showed good properties. The trisulfonated moieties and diphenyl ether simultaneously played important roles in improving the properties of the polymer.