Abstract A study has been made on the post-radiation grafting of aqueous acrylamide (AAm) onto polypropylene films (PP). A good hydrogel supported on the polymer substrate was obtained by grafting of AAm onto preirradiated PP films. The effect of grafting conditions such as solvent and inhibitor concentration, preirradiation dose, monomer concentration and reaction temperature on the initial rate and grafting yield was determined. It was found that the addition of 0.05 wt% Mohr's salt into the reaction medium effectively reduced the homopolymerization of AAm and the grafting process was successfully achieved. The dependence of the initial rate of grafting on the preirradiation dose and AAm concentration was found to be of the order 1.3 and 1.7, respectively. Two overall activation energies for this grafting system were found: 31.1 and 13.5 kcal mol −1 below and above 35°C, respectively. Some selected properties of the prepared graft copolymer were investigated and the possibility of its practical use discussed.