Ionic polymerization under electric field. I. Cationic polymerization of p‐methoxystyrene

The cationic polymerizations of p‐methoxystyrene with iodine in ethylene dichloride were carried out under strong electric field. It was found that the overall rate of polymerization was larger in the presence of the electric field than in its absence. After confirming that the field effect is neither due to the JOULE heat, nor related to the polymerization initiation by ionic species or radicals electrolytically produced, it was suggested that the field‐facilitated dissociation of ion‐pairs at growing chain ends may be responsible for the observed field effect, on the assumption that the rate constant of propagation of free ions was larger than that of ion‐pairs. It was also noticed that the degree of polymerization became larger under electric field. The radical polymerizations of styrene and methylmethacrylate were also performed under electric field. No field effect was observed in contrast to the cationic polymerization.