To improve water wettability of polyurethane (PU), graft copolymerization of acrylamide (AAm) and itaconic acid (IA) was performed using benzoyl peroxide (BO) initiator. The grafting reaction was carried out by placing the membranes in aqueous solutions of Aam and IA at constant temperatures. Variations of graft yield with time, temperature, initiator and monomer concentrations were investigated. The optimum temperature, polymerization time, initiator and monomer concentrations for AAm were found to be 80 degreesC, 2 h, 4.0x10(-2) M and 1.5 M and for IA, 80 degreesC, 1 h, 4.0x10(-2) M and 1.5 M, respectively. The membranes were characterized by FTIR spectroscopy and scanning electron microscopy (SEM) analysis and the effect of grafting on equilibrium water content (EWC) of PU membranes was obtained by swelling measurements. (C) 2000 Elsevier Science Ltd. All rights reserved.