Surface photografting polymerization of vinyl acetate (VAc), maleic anhydride, and their charge transfer complex. II. VAc(2)

On the basis of our earlier work, extensive experiments were conducted to f urther investigate grafting vinyl acetate onto different films (10 types of films and 20 binds of film combinations), using various photoinitiators, f or example, BP, AQ, ITX, XAN, Irgacure 651 and 184, acetone, and cyclohexan one, irradiated by UV radiation. Several means were applied to confirm the grafted PE-g-PVAc film. The results showed that increasing UV radiation int ensity is favorable for grafting polymerization and the far UV radiation pl ays a decisive role. Among the photoinitiators tested, BP is the best one, because it was found that BP initiates the grafting copolymerization effici ently, and other initiators are less effective. To various combined substra tes, the affinity between the monomer and films, the reactivity of hydrogen s on the substrates, and the transparence of the top film to UV radiation a re main factors affecting polymerization. Both direct method (FTIR) and ind irect methods (contact angle, color reaction, absorption of dye and water) verified the true product PE-g-PVAc. (C) 2000 John Wiley & Sons, Inc.