The grafting of acrylic acid onto poly(ethylene terephthalate) films with gamma radiation was carried out. The effects of different parameters, such as the monomer concentration, inhibitor concentration, and irradiation dose, on the grafting yield were investigated. The grafting yield depended on these parameters, and its maximum value was obtained at a 1.5% inhibitor concentration and a 40% monomer concentration. The obtained grafting films were characterized with water swelling measurements, differential scanning calorimetry, and thermogravimetric analysis. The results of differential scanning calorimetry showed decreases in the heat capacity step and the glass-transition temperature with increasing grafting yield. The ability of poly(ethylene terephthalate) to crystallize and the size of the crystalline domains were affected by the grafting. The grafted poly(ethylene terephthalate) that was obtained was tested as an ion exchanger for copper, nickel, cobalt, and lead., The capacity of the grafted films for ion recovery was dependent on the grafting yield. (c) 2006 Wiley Periodicals, Inc.