Facile preparation of blend proton exchange membranes with highly sulfonated poly(arylene ether) and poly(arylene ether sulfone) bearing dense triazoles

A novel series of blended polymer electrolyte membranes (PEMs) from crosslinked sulfonated poly(arylene ether) (cSPAE100) and triazole-containing poly(arylene ether sulfone) (PAES-DTM) were prepared for fuel cell applications. cSPAE100 with a high degree of sulfonation was synthesized via aromatic condensation. PAES-DTM densely functionalized with di-triazole moieties was blended with cSPAE100. The blend ratios of the fabricated PEMs varied from 2 wt% to 10 wt%, and the blend PEMs (cSPAE-DTMs) displayed sufficiently high ion exchange capacities (IEC = 2.07-1.86 mequiv/g). Introducing the triazole moieties, the proton conductivities of cSPAE-DTM2 and cSPAE-DTM5 increased at high relative humidity (95% RH), whereas their IEC values decreased. Furthermore, evaluation of the cell performance at 80 degrees C revealed that the performance of the cSPAE-DTMs was superior to that of the pristine membrane under 50% RH. For practical application in fuel cells, the thermal, chemical and mechanical properties of all membranes were investigated.