Crosslinked, epoxy-based anion conductive membranes for alkaline membrane fuel cells

Anion conductive polysulfone membranes were successfully crosslinked via epoxy functionalities resulting in improved mechanical properties. The concentration of the epoxy crosslinker, tetraphenylolethane glycidyl ether (4EP), controlled the degree of crosslinking. All the crosslinked membranes had good thermal stability, low water uptake, low swelling, and low methanol permeability compared to non-crosslinked membranes. The crosslinked membranes showed good dimensional stability in pure methanol while non-crosslinked ones were highly soluble. Although the ionic conductivity of crosslinked membranes was slightly lower, a higher selectivity (ratio of the ionic conductivity to the methanol permeability) was obtained.