SOME MODIFICATION ON RADIATION GRAFT-POLYMERIZATION OF N-VINYL-2-PYRROLIDONE ONTO LOW-DENSITY POLYETHYLENE WITH ALPHA,BETA-UNSATURATED NITRILE

N-Vinyl-2-pyrrolidone (NVP) was grafted onto low density polyethylene (LDPE) films using gamma-radiation by the direct method. The effect of grafting conditions such as inhibitor and monomer concentrations on t he grafting yield was investigated. The homopolymerization of NVP was reduced to a minimum using ferric chloride solution and the suitable c oncentration of the inhibitor was found to be 0.008 wt%. The grafted p olymer was modified using carbonitriles (2a-e). The swelling behaviour increases with the degree of grafting. It was observed that the swell ing behaviour of the modified grafted films with alpha-cyano-beta-(2-t hienyl)crotononitrile was an improvement on that of the grafted one. T he modification process for the grafted polymer was confirmed by IR sp ectrophotometry. The biological activity of the grafted films and the modified one with alpha-cyano-beta-(2-thienyl)crotononitrile was studi ed. The higher the degree of grafting the higher the carbonitrile reac ted. The results suggest that the biological activity of the modified grafted films was higher than that for the grafted one, under the same conditions. An improvement of hydrophilic grafted membrane by modific ation with some carbonitrile compounds showed great promise in some pr actical applications. (C) 1998 Elsevier Science Ltd. All rights reserv ed.