Photo-initiated thermal cross-linking behavior of acetophenone O-acryloyloxime-methyl methacrylate copolymer films in the presence of quinones

We have investigated the photo-initiated thermal cross-linking systems of acetophenone O-acryloyloxime (AAPO)methyl methacrylate (MMA) copolymer with quinones such as benzoquinone (BQ), 1,4-naphthoquinone (NQ) and 2-dodecylthio-1,4-benzoquinone (DTBQ). Quinones have been found to act as sensitizers of photolysis of acyloxyimino (AOI) groups. It is clarified that photo-cross-linking of AAPO-MMA copolymer films is due to the reaction of polymer radicals formed in the photolysis of AOI groups with quinones and that their post-thermal cross-linking is due to that of the resultant amino groups with quinones. NQ was most effective in the photo-cross-linking among the quinones. DTBQ was most effective for photo-assisted thermal cross-linking. (C) 2000 Elsevier Science Ltd. All rights reserved.