Benzophenone-1,3-dioxane as a free radial initiator for photopolymerization

Benzophenone-1,3-dioxane (BP-DO), a hydrogen abstraction type photoinitiator for free radical polymerization, is synthesized and characterized. Its capability for acting as an initiator for the polymerization of methyl methacrylate (MMA), styrene (St) and multifunctional monomers is examined. The relative photopolymerization efficiencies of BP-DO, benzophenone (BP), and BP/ethyl-4-dimethylaminobenzoate (EDAB) are compared. The amounts of leachable photoinitiator are determined through the extraction experiments. In contrast to BP-based photoinitiators, BP-DO does not require an additional hydrogen donor for the initiation; it could be a substitute for the conventional initiator systems of BP and BP/EDAB.