Radiation-induced graft polymerization of acrylonitrile onto isotactic polypropylene and poly(tetrafluoroethylene-ethylene) copolymer films

Direct radiation-induced grafting of acrylonitrile (AN) onto both isotactic polypropylene (IPP) and (tetrafluoroethylene-ethylene) copolymer (ET) films has been studied. The effect of grafting conditions such as inhibitor and monomer concentrations and irradiation dose on the grafting yield was investigated. Homopolymerization of acrylonitrile was reduced to a minimum using ferric chloride (FeCl3), and the suitable optimum concentration of the inhibitor was found to be 0.1 wt%. The higher the monomer concentration, the higher the degree of grafting obtained. It was observed that the degree of grafting onto IPP was higher than onto ET, at given grafting conditions. The effect of aging on IPP was also examined. IR spectroscopy showed that IPP was susceptible to photooxidation by aging. The swelling behaviour and electrical conductivity of the graft and hydrolysed graft films were investigated. The electrical conductivity was improved by hydrolysis of polyacrylonitrile in the graft chains.