CHANGES OF POLYMER MORPHOLOGY CAUSED BY UV IRRADIATION .2. SURFACE DESTRUCTION OF POLYMER BLENDS

The morphology of poly(methyl methacrylate)/polystyrene and poly(vinyl acetate)/polystyrene blends with different compositions was investiga ted by scanning electron microscopy. The multiphase structure and surf ace damage of blends caused by highly energetic, polychromatic u.v. ir radiation is presented. It was found that photodegradation of polymer blends was initiated at the phase boundary or in the phase of the less stable polymer. The changes which occur in interfacial interactions, probably caused by the formation of polar groups during photo-oxidatio n, are discussed.