Kinetic study of the photo-induced copolymerization of N-substituted maleimides with electron donor monomers

The photo-induced copolymerization of electron donor/electron acceptor mono mers has been studied by real-time infrared spectroscopy. With maleimide/vi nyl ether mixtures, the reaction was found to proceed rapidly upon u.v. exp osure in the absence of oxygen to reach nearly 100% conversion within secon ds. The two monomers disappeared at similar rates, with formation of an alt ernating copolymer. Similar results were obtained with maleimide/N-vinylpyr rolidone and maleimide/styryloxy combinations. Highly crosslinked polymer n etworks have been produced by photo-induced copolymerization of bis-maleimi de and divinyl ether monomers. These photoinitiator-free formulations were found to be less sensitive to oxygen inhibition than typical u.v.-curable a crylate resins. N-substituted maleimides were also shown to act as monomeri c photoinitiators by inducing the polymerization of acrylate monomers upon u.v. irradiation. (C) 1999 Elsevier Science Ltd. All rights reserved.