Novel ABPBI/POSS composite membranes for high-temperature PEMFC applications

Novel organic-inorganic composite membranes involving poly(2,5- benzimidazole) (ABPBI) and polyhedral oligomeric silsesquioxane (POSS) were prepared via in-situ synthesis followed by phosphoric acid doping. The formation of composites was characterized by SEM, XRD and FTIR. The results of water uptake showed that POSS cores emerged extraordinary water absorbability. When doping in phosphoric acid solution, phosphoric acid absorption in composites was dominated by functional groups linked to POSS cores. The excellent proton conductivities i.e. above 0.1S/cm at 100~160oC achieved from anhydrous ABPBI/OA-POSS composite membranes with 241wt.% of phosphoric acid absorption, make them very good candidates as the membranes for high temperature polymer electrolyte membrane fuel cell (PEMFC) applications.