Conversions in the surface layers of a polyvinylidene fluoride- polymethylmethacrylate compatible system in the glassy and highly elastic states and in the melt

Thin films (∼0·2 μm) of PVDF, PMMA and a 1 : 1 PVDF : PMMA mixture have been investigated by X-ray photoelectron spectroscopy. It has been established that the structure of the surface layers of the blended sample in the melt differ from the initial one obtained from solution. Some widening of the fluorine line and the appearance of an additional oxygen line in the X-ray electron spectrum of the blended sample indicate the existence of specific interactions between macromolecules of a varied nature responsible for compatibility in the system. Increase in T g of the thin layers in contact with air as compared with bulk samples of the same composition has been established. Heating the blended sample above 413 K resulted in the redistribution of the polymeric components in the surface layer leading to enrichment of the latter with polyvinylidene fluoride.