Crosslinked Electrolytes Based on Poly(butoxyMethylenenorbornene) for Proton Exchange Membrane

The poly(butoxymethylenenorbornene-co-norbornenemethyl acetate) (PBN/NA) were successfully synthesized via the vinyl addition copolymerization of 2-butoxymethylene norbornene (BN) and norbornene-2-methyl acetate (NA). The poly(butoxymethylenenorbornene-co-norbornenemethanol) (PBN/NOH) was obtained by the de-esterification of PBN/NA. After doping with 4,5-imidazole dicarboxylic acid (IDA) and phosphoric acid (H3PO4), the proton exchange membranes with crosslinked structure were obtained and the corresponding morphology, water uptake, proton conductivity, methanol permeability, thermal stability, as well as tensile properties were investigated. The results indicate that the crosslinked membranes showed higher proton conductivity at higher temperatures and lower methanol permeability after incorporation of more content of IDA and H3PO4. The PNIH membranes showed lower tensile strength, elongation at break as well as the elastic modulus than pristine PBN/NOH. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 123: 3225-3233, 2012