Synthesis and characterization of ASU-PPO based anion exchange membrane with PEG support for water electrolysis

Polymer electrolyte membrane-based water electrolysis technology is a productive method for converting electrical energy into hydrogen. To improve and optimize the performance of the water electrolytic system, an anion exchange membrane (AEM) water electrolyzer is an excellent choice. AEM possess inadequacies in cation structural design, and diversity in development approaches with each new cation inclusion. This study focuses on the synthesis and characterization of a variety of poly (2,6-dimethyl-1,4-phenylene oxide) (PPO)-based AEMs crosslinked with azonia-spiro undecane (ASU). The design process consists of three steps: first P-ASU making followed by quaternarization and then PPO bromination, followed by P-ASU and BPPO crosslinking. The membrane’s stability is enhanced by adding polyethylene glycol (PEG). PPO has outstanding mechanical and thermal stability, and its backbone can be functionalized through a variety of ways. Bromination was performed with quantitative control in this study. The developed membrane was examined using analytical tools (e.g., TGA, FTIR, HNMR, SEM). The results revealed that membrane demonstrated sufficient thermal stability between 150 °C and 250 °C as degradation phase. Characterization results also contribute to accurately measuring membrane surface morphology and stability at 4.38 ppm and 3.13–3.24 ppm transition from the–CH₂Br group to the–N+(CH₃)₃ groups by new peaks. The composition and properties were analyzed to validate successful crosslinking and functionalization of the membrane.