Fabrication and Characterization of Proton Conductive Membranes Based on Poly(methyl methacrylate-co-maleic anhydride)

In this study, proton conductive composite membranes were produced by using a poly(methylmethacrylate-co-maleic anhydride) (P(MMA-co-MAH)) copolymer and phosphotungstic Acid (PWA) as an additive of the proton conductive agent. P(MMA/MAH) 70/30, 50/50, and 30/70 were synthesized using a free radical polymerization reaction. PWA with a concentration of 2% was added to improve the performance of proton exchange membranes. Composite membranes of P(MMA30-co-MAH70)/PWA had the highest performance, and this improvement was attributed to the presence of MAH and PWA. By increasing the ratio of MMA:MAH from 30/70 to 70/30, thermal stability, ion exchange capacity and proton conductivity of membranes enhanced up to 310°C, 0.85 meq/g, and 5.77 mS/cm, respectively. Moreover, the addition of PWA into the membrane matrix improved the membrane characteristics so that thermal stability, ion exchange capacity, and proton conductivity increased to 317°C, 0.98 meq/g, and 14.42 mS/cm. The synthesized copolymer offered the required properties to be used for the fabrication of a proton conductive membrane.