Functionalizing of polyurethane surfaces by photografting with hydrophilicmonomers

Poly(ester urethane) (PU) with functional groups (amide, hydroxyl, carboxyl ) on surfaces were prepared by grafting monomers such as acrylamide (AAm), hydroxyethyl acrylate (HEA), and methacrylic acid (MAA) onto the PU membran es. Grafting copolymerization was carried out by the combined use of photoo xidization and UV irradiation grafting. The PU membrane was photooxidized i n hydrogen peroxide solution under UV light to yield hydroperoxide groups o n the surface and then irradiation grafting with monomer in water. The ATR- FTIR spectrum, X-ray photoelectron spectroscopy characterized the grafted c opolymers and verified the occurrence of grafting copolymerization. The res ults showed that the content of hydroperoxide groups yielded was dependent on the photooxidization time and reached maximum at about 8 h. Grafting cop olymerization was enhanced when irradiating by UV light. The degree of graf ting was increased with the increase of content of hydroperoxide groups, ir radiation time, and monomer concentration. The grafting copolymerization wa s enhanced when an appropriate amount of ferrous ions was added. After graf ting, the wettability of PU and the water absorption percentage increased w ith the degree of grafting. (C) 2000 John Wiley & Sons, Inc.