Graft Copolymerization by Pre-Irradiation Method

Effects of Water and Various Methods of Contact of Monomer

Abstract

Vinylpyrrolidone was grafted in its aqueous solution on to the various kinds of polymers (polyethylene, polypropylene, nylon-6 and viscose rayon) by pre-irradiation method. The accelerating effect of water on the grafting, which is generally recognized for the grafting onto hydrophilic polymers, is also found even for the hydrophobic polymers. This effect, however, cannot be observed in grafting at high temperature in some systems.
Various kinds of monomers (styrene, methyl methacrylate, methyl acrylate and acrylonitrile) were grafted in their emulsions onto the above stated polymers. In this method, the grafting does not depend on the monomer concentration in the broad range. This grafting is regarded as a special case of grafting in aqueous solutions of the monomer.
Furthermore, the grafting of methyl methacrylate onto polypropylene in its monomer vapor is similar to that in its monomer liquid, for the layer of monomer might cover the surface of the polymer in case of grafting in the vapor phase.