SURFACE ENRICHMENT OF THE SOLUTION-CAST POLY(METHYL METHACRYLATE) POLY(VINYL ACETATE) BLENDS

The surface enrichment of blend films of poly(methyl methacrylate) (PM MA) and poly(vinyl acetate) (PVAc) cast from various solvents has been investigated by contact angle, X-ray photoelectron spectroscopic and attenuated total reflection Fourier transform infra-red spectroscopic measurements. The composition of each component was fixed at 50 wt%. T he surfaces of miscible PMMA/PVAc blend films are found to be enriched in PVAc regardless of casting solvents. It was found that the surface enrichment of PVAc in the PMMA/PVAc blend is reduced when the as-cast blend film shows phase separation or when the phase-mixed blend is he ated above the lower critical solution temperature and exhibits therma lly induced phase separation.