PHOTOREDUCTION OF BENZOPHENONE BY 2,4,6-TRIMETHYL-1,3,5-TRITHIANE IN SOLUTION - LASER FLASH-PHOTOLYSIS STUDY

The role of 2,4,6-trimethyl-1,3,5-trithiane (TMT) in accelerating the initiation of polymerization induced by benzophenone (BP) was pursued by studying the primary photochemical reactions occurring between BP a nd TMT. Kinetic aspects of the quenching of the BP triplet by TMT were followed by laser flash photolysis. Triplet quenching rate constants and quantum yields for electron-transfer products were measured. In ad dition the mechanism of the photoreduction of BP by organic sulfides i n acetonitrile and mixed acetonitrile/water solutions is discussed. Ph otoinitiated polymerizations with a model monomer were carried out wit h some of the sulfide co-initiators investigated, and the polymerizati on behavior was correlated with the kinetic results. (C) 1998 Elsevier Science S.A.