(226e) Synthesis and Characterization of Poly(styrene-isobutylene-methyl vinyl ether) for Direct Methanol Fuel Cell Applications

Novel block copolymers based on poly(styrene) (PS), poly(isobutylene) (PIB) and poly(methyl vinyl ether) (PMVE) were synthesized using cationic polymerization. They were synthesized employing two different concentrations of PMVE. The resulting block copolymers were characterized using: Gel Permeation Chromatography (GPC), Fourier Transforms Infrared Spectroscopy (FT-IR), Thermogravimetric Analysis (TGA), and Differential Scanning Calorimetry (DSC). The block copolymers were then sulfonated and solvent casted into ionic polymer membranes (ionomers) for direct methanol fuel cell (DMFC) applications. The ionomers were characterized using several techniques: Elemental Analysis (EA), Thermogravimetric Analysis (TGA), water absorption, and Fourier-transform Infrared Spectroscopy (FT-IR). The techniques were used to identify the changes in the chemical and thermal properties of the membranes, as well as to evaluate changes in the resulting morphologies. Proton conductivity and methanol permeability were measured to understand how the different concentrations of PMVE influenced the transport mechanism of protons and methanol through the membrane for DMFC applications. Significant differences in their thermal, physical and transport properties were observed.