SEGREGATION BEHAVIOR FOUND IN POLY(2-ETHYLHEXYLACRYLATE) POLY(VINYLIDENEFLUORIDE-CO-HEXAFLUOROACETONE) BLENDS/

The surface and bottom compositions of poly(2-ethylhexyl acrylate) (P2 EHA)/poly-(vinylidene fluoride-co-hexafluoro acetone) [P(VDF-HFA)] ble nds were investigated by XPS analysis. In these blends, the enriched P (VDF-HFA) layer was observed from the top surface to a few nm depth, w hile the P2EHA component segregated at the bottom (the surface in cont act with release liner). The probe tack values of the bottom side were remarkably larger than those of the surface side for the P2EHA/P(VDF- HFA) blends because the characteristic segregation structure was forme d. We expected that the P2EHA/P(VDF-HFA) blends could be utilized as a non-backing pressure sensitive adhesive (PSA) tape. The effects of th e film thickness of the blends and the molecular weights of P2EHA on t he segregation structure were also examined. We thought that segregati on behavior found in P2EHA/P(VDF-HFA) blends was caused by several fac tors, such as surface tension, miscibility, density, and rate of solve nt casting.