RESEARCH ON IMPROVING THE EFFICIENCY AND SPECTRAL RESPONSE OF PHOTOPOLYMERIZATION.
Abstract:
The ultimate objective of this research program is the development of a nonsilver halide photographic process based upon photopolymerization. Work toward this goal was in three main areas 1 study of the effects of viscosity on photopolymerization 2 elimination of oxygen inhibition and 3 evaluation of efficient visiblelight-activated free-radical initiator systems. Studies into the kinetics of photopolymerization of acrylamide in gelatin slabs as a function of water content and the nature of the activator molecule showed that efficient polymer yields and molecular weights were obtained at water levels of 30 to 85, but lower yields were obtained at lower water levels. Oxygen removal was investigated with bisulfite ion, oxygen-carrying metal chelates, and enzymes. Although the bisulfite approach appears useless, the other two procedures warrant additional investigation. A re-evaluation of the kinetics and mechanism of photopolymer processes activated by acetylacetone and dimedon indicated that photoinitiation results from the reaction with the monomer of a lightexcited thionine-B-diketone complex. Author