The direct-irradiation-induced grafting of acrylamide onto polypropylene films and polystyrene films with crosslinking epichlorohydrin (Epi) as a spacer was studied. The reaction of polyamide-Epi with cellulose and starch was carried out. Fourier transform infrared spectroscopy, scanning electron microscopy, and thermogravimetric analysis were carried out before and after the enzyme was immobilized to confirm the characterization of the polymer and the alpha-amylase enzyme-immobilized one. The physico-chemical parameters of the immobilized enzymes were measured, and the kinetics of the coenzyme-polymer-catalyzed reactions and stability were investigated. A direct comparison was made between the activities of the free and immobilized preparations. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 112: 629-638, 2009