Synthesis of Polymeric Photoinitiators Containing Pendent Chromophore−Borate Ion Pairs: Photochemistry and Photopolymerization Activities

Poly(methyl methacrylate)s containing light-absorbing acetonaphthone and acetobenzo[ b ]furan as electron acceptors paired with tetraorganyl borates have been synthesized. Upon irradiation at 350 nm, oxidative carbon−nitrogen and reductive carbon−boron bond cleavage occurs, producing reactive radicals and tertiary amines. The efficiency of bond-breaking processes is found to be dependent on the nature of both the acceptors and the donors. Photoinduced polymerizations initiated by these polymeric initiators have been compared to 2,2-dimethoxy-2-phenylacetophenone (Irgacure 651) in tetraethylene glycoldiacrylate (TEGDA). Differences in the efficiency of the initation are accounted for by parameters associated with photoreactivity.