SURFACE ENRICHMENT IN THIN-FILMS OF PVC AND PMMA

The surface enrichment in thin bilayer films of poly(vinyl chloride) ( PVC) and deuterated poly(methyl methacrylate) (PMMAd) was studied by n eutron reflectometry. X-ray photoelectron spectroscopy (XPS) and stati c secondary ion mass spectrometry (SSIMS). In a layer system, where th e PVC film is placed on top of a thin PMMA film. the PMMA chains migra te to the surface, although annealing of the films is performed below the glass transition temperature of PMMA. In addition, the surface seg regation in blends of these materials was studied by XPS and SSIMS. In all cases PMMA is enriched at the surface. Results from the different techniques, probing different sample depths, are consistent, if an ex ponential concentration profile of PMMAd at the surface is assumed. Co ncentration profiles at the surface are discussed with respect to theo retical models and diffusion coefficients are estimated.