Synthesis of polymeric photoinitiators containing pendent chromophore-borate ion pairs: Photochemistry and photopolymerization activities

Poly(methyl methacrylate)s containing light-absorbing acetonaphthone and ac etobenzol[b]-furan as electron accepters paired with tetraorganyl berates h ave been synthesized. Upon irradiation at 350 nm, oxidative carbon-nitrogen and reductive carbon-boron bond cleavage occurs, producing reactive radica ls and tertiary amines. The efficiency of bond-breaking processes is found to be dependent on the nature of both the accepters and the donors. Photoin duced polymerizations initiated by these polymeric initiators have been com pared to 2,2-dimethoxy-2-phenylacetophenone (Irgacure 651) in tetraethylene glycoldiacrylate (TEGDA). Differences in the efficiency of the initation a re accounted for by parameters associated with photoreactivity.