Gamma radiation induced graft copolymerization of acrylate monomers onto isotactic polypropylene

Abstract

In an attempt to prepare synthetic memberanes for use in desalination of water and as speciality polymeric materials modification of isotactic polypropylene (IPP) by graft copolymerization has been studied. Grafting of acrylate monomers such as acrylonitrile (AN), acrylamide (AAm) and acrylic acid (AAc) onto IPP has been effected by gamma rays from a 2100 ci Co 60 source in air. The preirradiated IPP on heating in the presence of vinyl monomers affords grafting. Different solvents were found to influence grafting. The relative ability of different solvents towards grafting of AN onto IPP was found to follow the order: ▪ Whereas for grafting of AAm and AAc the order observed is: ▪ The percentage of grafting was determined as a function of various reaction parameters. Effect of alcohols of varying chain length upon percentage of grafting of AN onto IPP was studied. Alcohols were found to vary in their ability to influence grafting and the following reactivity order was observed: n – pentanol > n–butanol >tert– >n–propanol >ethanol > isopropanol. A plausible mechanism for graft copolymerization of acrylate monomers onto preirradiatedIPP has been proposed to explain the solvent effects on percentage of grafting. The graft copolymers have been characterized by IR spectroscopic and thermogravimetric methods. Evaluation of grafted polymers as membranes for the desalination water is in progress.