A NOVEL VISIBLE-LIGHT SENSITIVE DYE-ONIUM SALT PHOTOINITIATOR
新型感可见光的染料鎓盐光引发体系

A new visible-light sensitive photoinitiator, bis (diphenyl-iodonium) salt of eosin, is reported. This system has good thermal stabi ity in ground state. When excited, it can undergo intra-ion-pair electron transfer, leading to the bleaching of the dye and the decomposition of the onium salt. The later results in the formation of initiating radical species. This system can be used as a photoinitiator in radical polymerization of conventional vinyl monomers, especially for acrylates. When methyl methacrylate (MMA) is chosen as the monomer,the polymeri-zation satisfeis the following kinetic equation. The activation energy of polymerization was obtained to be Ea=7.00kcal/mol. In the poly-merization system,oxygen acted not only as the inhibitor of polymerization,but also as the quencher of the triplet of the initiator.