Studies in photopolymerization IV: Photopolymerization of methyl methacrylate using peroxydiphosphate as a photoinitiator

Photopolymerization of methyl methacrylate was carried out using peroxydiphosphate as a photoinitiator. The rate Rp of polymerization increases as the initiator mole fraction is increased. The initiator exponent was computed to be 0.5. The rate of polymerization increases with increasing monomer concentration and the monomer exponent was calculated to be 1.5. The reaction was carried out at three different temperatures and the overall activation energy was computed to be 4.7 kcal mol−1. The kinetic data and other evidence indicate that the overall polymerization takes place by a radical mechanism, and rate expressions have been derived. A suitable mechanism has been suggested.