OZONE-INDUCED GRAFT-POLYMERIZATION ONTO POLYMER SURFACE

Ozone-induced graft polymerization was carried out to improve polymer surfaces. The polymers were exposed to ozone and the surface density of peroxides formed was determined by three methods; iodide, DPPH, and peroxidase method. The peroxide production could be readily controlled by the ozone concentration and the ozone exposure time. In addition, it was dependent on the kind of polymer. Further, it seemed probable that the ozone oxidation introduced peroxides not only on the outermost surface but also into a layer deeper from the outermost surface. Such polymeric peroxides were capable of initiating graft polymerization onto PU. All the physical and biological measurements on the grafted surface indicated that ozone-induced graft polymerization has effectively made the PU surface covered with the grafted water-soluble chains, their location being restricted to the film surface region. The interaction of the PU surface with blood components could be greatly reduced by the surface graft polymerization.