Radiation copolymerization of acrylonitrile with polystyrene and perchlorovinyl
Abstract
Abstract With the objective of obtaining polymers with new, valuable properties in recent years considerable importance has been attached to the synthesis of graft and block copolymers. Such copolymers combine the properties of their polymeric constituents. In order to form graft and block copolymers it is necessary that the starting material possess active centers, which may be groups capable of forming free radicals. To carry out a graft or block copolymerization various chemical and physical methods yielding polymeric free radicals are employed. One of the new methods of synthesizing graft and block polymers is the radiation method. In the present work the results of experiments on the formation of graft polystyrene and perchlorovinyl polymers with acrylonitrile by the action of gamma rays are presented. Co™ served as radiation source. The reaction was carried out by subjecting a swollen polystyrene film in acrylonitrile to doses of 1 × 10 6 −4 × 10 6 r. The resultant product was separated from the homo‐polymer by extraction. As the results obtained have shown, the percentage of grafting over the range studied increases with increasing radiation dose. The monomer unit to polymer ratio has been calculated from data on the nitrogen content. Also a graft polymer of perchlorovinyl and acrylonitrile was obtained by preliminary irradiation of perchlorovinyl in the presence of air. The thermomechanical properties of the resultant polymers were investigated. The results showed that graft polymers of polystyrene and perchlorovinyl possess greater thermal stability than the initial polymers. In the study the radiation polymerization of acrylonitrile was also carried out and the viscosity of polyacrylonitrile solutions was measured.