POLYMERIZATION PHOTOINITIATED BY CARBONYL COMPOUNDS. VI. MECHANISM OF BENZIL PHOTOINITIATION.

In the reported experiments, the mechanism of the photoinitiation of the vinyl polymerization sensitized by benzil and 4,4 prime -dimethoxybenzil was studied. The monomers considered were methacrylic acid esters and styrene derivatives. All these monomers are efficient quenchers of the excited triplet benzil. However, the initiation efficiency of the benzil is important only when styrene derivatives mechanism. The initiation step is a consequence of the interaction (triplet benzil-monomer double bond) through a charge transfer complex.