Preparation of alkaline anion exchange polymer membrane from methylated melamine grafted poly(vinylbenzyl chloride) and its fuel cell performance

Abstract

A new material based on aminated and cross-linked methylated melamine grafted poly(vinylbenzyl chloride) was synthesized and used as a membrane for an alkaline anion exchange membrane fuel cell (AAEMFC). FT-IR spectra showed successful methylation of melamine and the ammonium quaternisation of the synthesized materials. DSC tests showed that the synthesized material had a high glass transition temperature, around 146 °C, and TGA showed the degradation temperature was 150 °C. The ion exchanged membrane tensile stress was 12.1 MPa, and the Young's Modulus was 0.142 GPa with a fractured elongation of 14%. The anion through plane conductivity increased from 1.3 × 10⁻² to 1.7 × 10⁻² S cm⁻¹ when the temperature was increased from 25 °C to 60 °C. The optimum ionomer loading in membrane electrode assemblies (MEAs) used in fuel cells was around 20 wt% for the synthesized ionomer. The power density of the fuel cell was 156 and 76 mW cm⁻² at room temperature (15 °C) with O₂/H₂ and H₂/air fuel cells, respectively. These results show that the resultant membrane is a promising material for the AAEMFC.