Preparation and properties of epoxy copolymers containing oxime-urethane groups as photobase generators

Epoxy copolymers containing oxime urethane groups were prepared by the poly merization of glycidyl methacrylate and N-[5-(benzophenoneoximinocarbonylam ino)pentanyl]maleimide (BOPM). Their physical properties were characterized by GPC, DSC and TGA analyses. Photochemical changes of the copolymers were studied by UV, IR spectroscopy, and contact angle measurements. A photoind uced cross-linking reaction in copolymer films was observed by measuring th e insoluble fraction. Irradiation of the copolymers at 254 nm UV light lead s to the formation of pendant amino soups by photodissociation of the oxime -urethane groups. Treatment of the amino groups with HCl resulted in the fo rmation of ammonium salts, which changed the polymer surface to be hydrophi lic. An insoluble fraction of the copolymers increased with irradiation tim e, heating time, and heating temperature. Cross-linking of the epoxy resin effectively catalyzed by the photogenerated pendant amines upon heating.