Development and characterization of crosslinked PPO-based anion exchange membranes for AEM fuel cells

This work describes the synthesis and characterization of a series poly(2,6-dimethyl-1,4-phenylene oxide) (PPO)-based anion exchange membranes (AEMs), crosslinked with bis-imidazolium cations, investigated as potential ionic conductors for AEM fuel cells. PPO has excellent mechanical thermal properties, its backbone can be functionalized by means several possible routes. Among them, bromination was carried out quantitative control amount linked halogens. degrees 14 mol% 33 were employing new procedure 1,6-bis(2-methylimidazol-1-yl)hexane (bimh). crosslinking method granted fast highly efficient reaction, resulting in an almost substitution bromine atoms (higher than 94%). The obtained cast thoroughly characterized thermogravimetry, 1H NMR, ATR-FTIR EDX spectroscopies, their properties assessed through evaluation water uptake (WU) swelling ratio (SR), well alkaline stability ex-situ conductivity electrochemical impedance spectroscopy (EIS). WU EIS tests conducted function temperature 20–100 °C range conditions complete hydration (95% relative humidity). prepared AEMs appeared well-uniform, retention ion-carrying abilities properly controlled affected increment degree PPO. Water rose while increasing degree, up to maximum 22.3% 140.6 mS cm−1 at 100 °C, respectively, consequence increased number sites that anchor OH− ions.