Commercial Monomer Availability Leading to Missed Opportunities? Anion-Exchange Membranes Made from meta-Vinylbenzyl Chloride Exhibit an Alkali Stability Enhancement

Abstract

Benzyltrimethylammonium-type anion-exchange polymers are common in alkali membrane fuel cells and water electrolyzers, but they suffer from degradation under alkaline conditions. Radiation-grafted anion-exchange membranes exhibit an alkali stability enhancement when made using noncommercial meta-only vinylbenzyl chloride (VBC) monomer, compared to the use of commercially available para-only or meta/para-mixed VBC isomers. We hypothesize a mechanism on why the use of meta-VBC eliminates AEM degradation via chain scission.