Photo-induced grafting polymerization of acrylamide (AAM) onto polyetherurethane (PEU) was studied with benzophenone (BP) as sensitizer under irradiation of 365 nm. The effects of irradiation time

concentrations of monomer and sensitizer on the grafting yield were investigated. The formatioin of graft copolymer was verified by its water absorption % and the scanning electron microscopy photographs. Some model compounds of PEU soft segment and hard segment were used to clarify the graft reaction mechanism

which was proposed to involve the hydrogen abstraction by excited triplet BP from a-carbon of the polyether segment and fr-om nitrogen of the hard segment. The produced redicals then initiate the graft polymeriza-tion.