ANALYSIS OF SURFACE SEGREGATION IN BLENDS OF ACRYLATE COPOLYMER WITH FLUORO-COPOLYMER

The surface segregation of poly(2-ethylhexyl acrylate-co-acrylic acid-co-vinyl acetate) P(2EHA-AA-VAc)/poly(vinylidene fluoride-co-hexafluoro acetone) P(VDF-HFA) blends was investigated by FTIR in surface analysis, the miscibility of blends examined by both the Prigogine-Flory-Patterson's theory and the thermo-photometry and surface tension gamma(s). From 1 to approximately 2-mu-m of the surface in P(2EHA-AA-VAc)/P(VDF-HFA) (50/50) blend, the variation in P(VDF-HFA) concentration with increasing distance from the surface was observed by use of ATR-FTIR with incidence angle dependence. It was suggested that the surface segregation of P(VDF-HFA) took place in the blends. The P(2EHA-AA-VAc)/P(VDF-HFA) blends were revealed to be heterogeneous systems by the results of state parameters and thermo-photometry. The gamma(s) of P(2EHA-AA-VAc) and P(VDF-HFA) were evaluated according to Prigogine's corresponding state theory, as extended for surfaces by Patterson and co-workers. The values of gamma(s) of P(2EHA-AA-VAc) and P(VDF-HFA) were 28.3 and 20.4 (dyn cm-1), respectively. Therefore, it was expected that surface segregation in P(2EHA-AA-VAc)/P(VDF-HFA) blends may occur, when the blend is immiscible and difference in gamma(s) between components is large.