A study of the photopolymerization kinetics of methyl methacrylate using novel benzophenone initiators

A series of novel bifunctional photoinitiators with benzophenone moieties were synthesized. Characterization of these molecules was performed using IR, UV, (HNMR)-H-1, (CNMR)-C-13 and mass spectroscopy. Photopolymerization of methyl methacrylate, a model acrylate-type monomer, was carried out with the bifunctional benzophenone molecules functioning as the photoinitiator and triethylamine as the co-initiator. The progress of the polymerization was followed by dilatometry. The resulting plots of monomer conversion with time were used to evaluate the initial rates of polymerization. The relative enhancement/lowering of the rates of polymerization, with respect to benzophenone as the model photoinitiator, are interpreted in terms of the structure, and the photophysics of the initiator evaluated by nanosecond laser flash photolysis. (C) 2001 Society of Chemical Industry.