Research Information System
JOURNAL OF POLYMER RESEARCH, vol.20, no.9, 2013 (SCI-Expanded)
Polymer electrolytes that have ability to conduct protons at high temperatures have become crucial as the membranes for proton exchange membrane fuel cells (PEMFC) in anhydrous systems. In this work, a novel copolymer based on 5-(methacrylamido)tetrazole (MTet) and vinyl triazole (VTri) was prepared by conventional free-radical copolymerization at several monomer feed ratios to attain poly(VTri-co-MTet) copolymers. The copolymer samples were doped with H3PO4 at several stoichiometric ratios to obtain proton conductive copolymer electrolytes. The obtained membranes were analyzed by FTIR, H-1-NMR, Thermogravimetric Analysis (TGA), Differantial Scanning Calorimetry (DSC), Scanning Electron Microscopy (SEM), Cyclic Voltammetry (CV), and Impedance Spectroscopy. The compositions and molecular weights of copolymers were determined via H-1-NMR analysis. TGA demonstrated that the copolymers are thermally stable up to approximately 220 degrees C. DSC results illustrated both the homogeneity of the materials by the appearance of a single T-g and the plasticizing effect of the dopant. SEM analysis provided further evidence for the homogeneity of the membranes. CV results demonstrated that the stability window of P(VTri-co-MTet) is 3 V. The copolymer electrolytes, P(VTri-co-MTet) 2: 1 X=2, P(VTri-co-MTet) 1: 1 X=2, and P(VTri-co-MTet) 1: 2 X=2 showed maximum proton conductivities of 0.012 Scm(-1), 0.014 Scm(-1) and 0.016 Scm(-1), respectively, at 150 degrees C and anhydrous conditions.