A sequential photoinitiation. phenomenon was found in the benzophenone/triethylamine/ MMA radical photopolymerization system

which leads to increase of molecular weight

amine content of polymer formed with progressive irradiation time. The results

obtained demonstrate that the sequential photoinitiation originates from the photoreaction of active amine groups at the polymer chains with excited benzophenones producing a polymer radicals

which induce sequential polymerization. The effects of benzophenone and amine concentrations

oxygen co-ntent and chain requlator were studied. Reaction mechanism was also discussed.