Novel anion exchange membrane with low ionic resistance based on chloromethylated/quaternized‐grafted polystyrene for energy efficient electromembrane processes

ABSTRACT

A novel anion‐exchange membrane has been manufactured by chloromethylation and subsequent quaternization of polystyrene within a graft copolymer films based on UV‐oxidized polymethylpentene. Particular attention is given to the kinetics of chloromethylation and the influence of the reaction conditions on the properties of the anion‐exchange membranes. By means of variation of the polystyrene content and its crosslinking degree we have obtained membranes that have an ion‐exchange capacity from 1.1 to 2.9 mmole g⁻¹, anion transport numbers between 91.0 and 95.5% and specific ionic conductivities ( ranging from 2 to 25 mS cm⁻¹. The developed membranes due to their low thickness and high conductivities have a remarkably low surface ionic resistance of around 0.6 Ω cm². It was calculated that the use of the developed materials will increase the efficiency of reverse electrodialysis energy production by 8–10% compared to the state of the art membranes. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 137, 48656.