Recent Progress of Photo- and Radiation-Induced Ionic Polymerizations

Photoinduced ionic polymerizations of the monomers α-methylstyrene, cyclohexeneoxide, nitroethylene, and acrylonitrile were carried out in the presence of electron acceptor or donor molecules. These polymerizations are proved to be initiated by ions formed through the dissociation of the photoexcited electron donor-acceptor complex and to proceed by ionic mechanism.

The molecular weight distribution of the polymer and the light intensity dependency on the rate of polymerization indicate that free ionic and ion-pair propagations coexist in the cationic polymerization of α-methylstyrene.

Anionic polymerizations were observed for the nitroethylenetetrahydrofuran and acrylonitrile-dimethylformamide systems.

Radiation-induced cationic polymerizations of styrene and α-methylstyrene were found to proceed by free cationic propagation. The effect of added electron acceptors in these polymerizations was investigated.