AbstractGraft‐copolymerization of acrylamide (AAm) on poly(ethylene terephthalate) (PET) films using benzoyl peroxide (Bz2O2) initiator has been studied. Four organic solvents, namely, pyridine (Py), 1,2‐dichloroethane (DCE), DEC/H2O (20/80, v/v), and dimethyl sulfoxide (DMSO), were used as swelling agents. DMSO was found to be the most suitable swelling agent. Solvent inclusion in the films increased with increased length of solvent treatment time and temperature. Elevated temperatures had a greater effect on the inclusion of swelling agents than did the length of swelling. Variation of graft yield with the type of solvent, initiator concentration, monomer concentration, temperature, and polymerization time were also investigated. The graft yield increased in the order of toluene, benzene, DMSO. The optimum temperature for grafting was found to be 70°C. The graft yield was observed to increase with monomer concentration and polymerization time, then reached a plateau. The graft yield increased up to a certain Bz2O2concentration, then decreased. © 1993 John Wiley&Sons