Modified Sulfonated Poly(arylene ether sulfone) Membranes Prepared via a Radiation Grafting Method for Fuel Cell Application

Sulfonated poly(arylene ether sulfone) (SPAES) membranes grafted with acrylic acid were prepared using a radiation method. After the irradiation step, the sulfonic acid groups and the polymer backbone of the SPAES membranes showed no signs of decomposition. The radiation-grafted SPAES membranes in their protonated form had relatively low grafting ratios due to the repulsion effect of the negative charge between sulfonic acid and acrylic acid. A higher acrylic acid grafting ratio made the radiationgrafted membranes more hydrophilic, resulting in higher proton conductivity but lower methanol permeability. Overall, introduction of the appropriate acrylic acid can help improve the fuel cell performance of radiation-grated SPAES membranes. (equation presented).