GAMMA-RAY INDUCED GRAFT-COPOLYMERIZATION OF N-VINYLPYRROLIDONE, ACRYLAMIDE AND THEIR MIXTURES ONTO POLYPROPYLENE FILMS

The radiation initiated grafting of N-vinylpyrrolidone (NVP) acrylamid e (AAm) and their mixtures onto polypropylene (PP) films using a direc t radiation technique has been investigated. Different solvents were u sed for diluting the monomers and it was found that dioxane was suitab le for this grafting system. The influence of other grafting parameter s such as inhibitor, monomer concentration and dose rate on the rate o f grafting and grafting yield was studied. The values of the coefficie nts relating the grafting rate to monomer concentration and dose rate were found to be 1.4 and 1.5 for (NVP), and 1.6 and 1.47 for (AAm), re spectively. Also, the coefficients relating grafting rate to comonomer concentration for 20/80 and 50/50 AAm/NVP mixtures were found to be 1 .6 and 1.7. Some physicochemical properties such as swelling, thermal behaviour, mechanical and electrical conductivity were also investigat ed, and the possibility of some practical uses, e.g. the removal of he avy metals from solution, for the grafted membranes is discussed. (C) 1998 SCI.