PHOTOMODIFICATION OF A POLY(ACRYLONITRILE-CO-BUTADIENE-COSTYRENE) CONTAINING DIARYLTETRAZOLYL GROUPS

A new type of membrane polymer, containing a photosensitive moiety, wa s synthesized. The photochemically induced functionalization and cross linking of ene-co-2-(4-ethenyl)phenyl-5-phenyl-2H-tetrazole], ABSV, ha s been studied. A variety of dipolarophiles and phenolic compounds wer e applied to alter the polarity of the membrane surface. The functiona lization and crosslinking were initiated by photoirradiation. DSC and contact angle measurements were used to characterize the modified poly mer. Pervaporation experiments with a cyclohexane/benzene mixture (5 w t % benzene) were carried out, with the results showing, that the phot ochemical treatment significantly effects both permselectivity and flu x. Solubility parameters were found to be useful to interpret the perv aporation data. In general, the selectivity towards benzene increases with the polarity of the membrane surface, i.e., with increasing polar ity of the modifier. A mechanism to explain the influence of both func tionalization and crosslinking on the membrane performance, is propose d. (C) 1994 John Wile & Sons Inc.