RADIATION-INDUCED POLYMERIZATION OF METHYL METHACRYLATE AND ALKYL ACRYLATES AT HIGH DOSE RATE.

Polymerization of methyl methacrylate and methyl, ethyl, and n-butyl acrylates was carried out in a wide range of dose rate, 10-10**6 rad/s by gamma -ray and electron beam irradiation. With methyl methacrylate and n-butyl acrylate, and steady-state kinetics in radical polymerization was maintained in an entire dose rate range at about the initial stage of the polymerization. With methyl and ethyl acrylates, the rate of polymerization increased much less markedly than expected from the square root law and the molecular weight decreased much less gradually with dose rate. In all these monomers it was found that autoacceleration of the rate of polymerization due to gel effect becomes vague at high dose rate.