One-pot preparation of anion exchange membranes from bromomethylated poly(2,6-dimethyl-1,4-phenylene oxide) for electrodialysis

• QPPO anion exchange membranes were prepared by the one-pot method.
• Membrane morphology is tunable by controlling the solubility parameter of solvent.
• Performances of one-pot prepared membrane are better than those of post-modified one.
• QPPO membranes are qualified for ED with low energy assumption.

Anion exchange membranes (AEMs) are commonly prepared by the heterogeneous post-modification of chloromethylated polymer films in trimethylamine (TMA) aqueous solution for the poor solubility of quaternary ammonium-functionalized polymers. This study reports the one-pot preparation of solvent-processable quaternary ammonium-functionalized poly (2,6-dimethyl-1, 4-phenylene oxide) (QPPO) solution by piping TMA gas into polymer solution directly. Solvents mixture with a proper solubility parameter is employed to ensure the dissolving of reactants and ammonium-functionalized products. Membrane morphology and properties, including ion exchange capacity, water uptake, area resistance, tensile strength and transport number, have been characterized to determine advantages of this strategy over the post-modification method. Moreover, the optimized membrane exhibits a better electrodialysis performance than that of post-modified membrane, suggesting the benefit of this strategy.