A STUDY OF THE GAMMA-RADIATION INDUCED MOLECULAR-WEIGHT CHANGES IN POLY (PHENYL METHACRYLATE), POLY (METHYL-METHACRYLATE) AND THEIR COPOLYMERS

The homopolymers and copolymers of phenyl methacrylate and methyl meth acrylate synthesized by free radical polymerization were characterized by infra red and nuclear magnetic resonance spectroscopy. The molecul ar weight changes produced as a result of gamma irradiation in an argo n atmosphere were monitored as a function of dose absorbed by the samp le. The radiation induced effects have been discussed in terms of G(Sc ission), energy absorbed per break and number of bonds broken per gram in a polymer sample. The results reveal that poly (phenyl methacrylat e) is more stable than poly (methyl methacrylate) while, the radiation stability of the copolymers depends upon the concentrations of the re spective monomers.