Poly(arylene ether)s with Pendant Perfluoroalkyl Sulfonic Acid Groups as Proton-Exchange Membrane Materials

New membranes were prepared and evaluated as polymer electrolytes for PEMFCs. Polymers with PSU in the main chain and -C(O)(CF2)(3)SO3H in the side chain (PSU-PSA) were synthesized by substitution of PSU-Li and SFBF, followed by treatment with aqueous potassium hydroxide then sulfuric acid. The proton conductivity of PSU-PSA with an ion exchange capacity (IEC) of 1.12 mmol.g(-1) was 0.091 S.cm(-1) at 80 degrees C under 100% relative humidity. A hydrogen/air PEMFC test of PSU-PSA with an IEC value of 1.12 mmol.g(-1) produced a maximum power output of 0.265W.cm(-2). A DMA measurement revealed that PSU-PSA had an a-relaxation temperature around 196 degrees C which is higher than the value reported for Nafion.