Radical Inhibitors Assisted Alkali-Resisting Anion Exchange Membranes Based On Poly(4-Vinylbenzyl Chloride-Styrene)

It is found that free radicals of (OH)-O-center dot would be generated in KOH solutions at elevated temperatures according to the results of fluorescence analysis. Five kinds of radical inhibitors (tert-butylphenol-containing reagents, 4-amino-tempo, benzophenone, phenothiazine and N-phenyl-1-naphthylamine) were employed as the dopant, separately, to prepare anion exchange membranes (AEMs) based on poly(4-vinylbenzylchloride-styrene). The investigaions on the properties of the prepared AEMs indicate that more radicals might be produced during the degradation of the AEMs via chain propagation reactions. Moreover, the influences of the radical inhibitors on the degradation of the AEMs in 8 M KOH solutions at 80 degrees C are quite different although all these inhibitors could react with (OH)-O-center dot radicals. Therein the radical inhibitors o-, m-, p-tert-butylphenols could effectively enhance the chemical stability of the AEMs. However, when the phenol-containing inhibitors have a large substituent group in its benzene ring, the membranes tend to be brittle during the stability test.