New PBI Membranes Doped with Methyl-Imidazolium Triflate Protic Ionic Liquid

In this study, new proton conducting membranes were prepared using poly-2,2'-(m-phenylene)-5,5'-bibenzimidazole (PBI) and varying amounts of methylimidazoliumtriflate[MeIm/TfO], a protic ionic liquid, by the solution casting method. The thermal properties and conductivity of these membranes were investigated. The obtained parameters, such as high thermal stability (235–255°C) and the conductivity of 0.7–1.6 mS/cm at 145°C, indicate that PBI membranes doped with either MeIm/TfO or BuIm/TfO, which were previously studied by our group, are quite interesting for further investigation as potential electrolytes for PEMFCs.