γ-Ray Induced Vapor-phase Graft-polymerization of Methyl Methacrylate onto Poly(propylene)

Abstract

The vapor-phase graft-polymerization of methyl methacrylate onto poly(propylene) fibers was studied by a T-ray simultaneous irradiation technique and the weight increase during the reaction was followed by a spring balance. The sorption of methyl methacrylate onto poly(propylene) fibers approached to the apparent equilibrium after 60 to 180 minutes from the introduction of the vapor and the equilibrium sorption was lowered with rising the temperature. The sorption was augmented with the increase in the extent of grafting. The rate of weight increase of fibers due to the grafting reaction became larger with rising the reaction temperature, the vapor pressure of monomer and the irradiation dose rate. The grafting proceeded linearly with the irradiation time when the vapor pressure of monomer was low, but the acceleration was observed when the vapor pressure of monomer was high. The grafted fibers contained the large amount of the occluded homopolymer. The grafting reaction process, and the dependency of the rate of grafting on the temperature, vapor pressure, and dose-rate were well explained by taking into account of the increase in sorption caused with the increase in the extent of grafting.