SURFACE SEGREGATION AND TACKINESS IN BLENDS OF POLY(VINYLIDENE FLUORIDE-CO-HEXAFLUORO ACETONE) WITH POLY(2-ETHYLHEXYL ACRYLATE-CO-ACRYLIC ACID-CO-VINYL ACETATE)

In the blends of poly(vinylidene fluoride-co-hexafluoro acetone) P(VDF-HFA) with poly(2-ethylhexyl acrylate-co-acrylic acid-co-vinyl acetate) P(2EHA-AA-VAc), the surface composition was investigated with X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM), and the tackiness was evaluated using the J. Dow ball tack and dynamic mechanical analysis. From surface to a few nm in depth, in the P (VDF-HFA)/P(2EHA-AA-VAc) (50/50) blend, the variation in P(VDF-HFA) concentration, with increasing distance from the surface, was found by means of XPS with take-off angle dependence. It was confirmed that surface segregation of P (VDF-HFA) in the P (VDF-HFA)/P(2EHA-AA-VAc) blends took place. The value of J. Dow ball tack of the surface side in the P (VDF-HFA) / P (2EHA-AA-VAc) blends was smaller than that of bottom side in blends. The delineation of dynamic loss factor DELTA vs. the temperature curve of the surface side in a (50 / 50) blend differed from that of the bottom side. It was suggested that surface segregation affected the difference in tackiness between the surface side and the bottom side. (C) 1993 John Wiley & Sons, Inc.