Novel, highly efficient polymeric benzophenone photoinitiator containing coinitiator moieties for photopolymerization

A novel polymeric photoinitiator P(MPBP-co-DMAEMA), bearing side-chain benzophenone (BP) and coinitiator amine, was synthesized through free radical copolymerization of a polymerizable photoinitiator, 4-[(4-maleimido) phenoxy] benzophenone (MPBP), and a polymerizable coinitiator amine, N,N-dimethylaminoethyl methacrylate (DMAEMA). In order to find out the influences of coinitiator amine on photopolymerization, a polymeric coinitiator amine, P(DMAEMA), was also synthesized for comparison. FT-IR, H-1 NMR, and GPC analyses confirm the structures of polymers. The UV-Vis spectra of polymeric photoinitiator P(MPBP-co-DMAEMA) and polymerizable photoinitiator MPBP are similar, and both exhibit high red-shifted maximal absorption as compared with BP. The photopolymerization of 1,6-hexanediol diacrylate (HDDA) and trimethylolpropane triacrylate (TMPTA), initiated by MPBP/DMAEMA, MPBP/P(DMAEMA), and P(MPBP-co-DMAEMA) systems, was studied by photo-DSC. The results indicate that P(MPBP-co-DMAEMA) is most efficient for the polymerization of both HDDA and TMPTA, and MPBP/P(DMAEMA) is the least efficient of the three photoinitiating systems. Copyright (C) 2009 John Wiley & Sons, Ltd.