Quaternized poly(aromatic ether sulfone) with siloxane crosslinking networks as high temperature proton exchange membranes

Novel high temperature proton exchange membranes, quaternized poly(aryl ether sulfone) (QPAES), were prepared using triethylamine (TEA) as quaternization reagent and (N, N-diethyl-3-aminopropyl) trimethoxysilane (EPMS) as the crosslinking agent, respectively. To improve the mechanical strength and dimensional stability of the membranes, the crosslinked structure of Si-O-Si network was formed by hydrolyzing siloxane groups of EPMS. Compared with the non-crosslinked membrane, the crosslinked PAES membranes displayed significantly enhanced mechanical properties, improved dimensional stabilities as well as high conductivities. The QPAES-10EPMS-90TEA membrane with a phosphoric acid doping level of 12.1 exhibited a tensile strength of 9.16 MPa at room temperature, and a conductivity of 74.8 mS cm(-1) at 180 degrees C under no humidification conditions.