Abstract: The surface properties of a series of segmented and graft copolymers and.blendscontaining polydimethylsiloxane(PDMS )have been investigated by XPS.It is shown thatenrichment of PDMS soft segments or molecules occurs on the surface of the segmentedcopolymers as well as on that of graft copolymers and blends. The order of degree of enrich-ment is as follows:blends>graft copolymers>segmented copolymerss,which is explainedas a resuIt of the easiness of movement of the PDMS segments or molecules.Meanwhile,compatibility between the different components(or phases)of the copolymers or blends is ofdisadvantage to enrichment of PDMS on the surface.

Key words: polydimethylsiloxane, polysulfone, polyhydroxystyrene, segmented copolymergraft copolymer, blend, surface enrichment, XPS