Fundamental studies of a new series of anion exchange membranes: membrane preparation and characterization

Chemical cross-linking anion exchange series membranes were prepared from l inear engineering plastics poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) by conducting the processes of bromination and amination at both benzyl and ar yl positions. Compared with the traditional technologies, the membrane rout e described in this paper has cancelled the chloromethylation process and t hus, given up the use of chloromethyl methyl ether, which has been consider ed as a potential harmful toxicity material. The ion exchange capacity, wat er content, membrane potential and transport number of membranes were studi ed. The results show that the membrane properties are significantly affecte d by the bromination processes benzyl-substitution will enhance the ion exc hange capacity and water content, while the aryl-substitution will decrease the water content with approximately unchanged ion exchange capacity. By p roperly balancing them, a series of membranes can be obtained to comply wit h different industrial requirements, such as diffusional dialysis, electrod ialysis, and water splitting processes. (C) 2001 Elsevier Science B.V. All rights reserved.