Interfacial tension of poly(ethylene-co-vinyl alcohol) polyamide blends

Interfacial tensions (gamma) between poly(ethylene-co-vinyl alcohol) (EVOH) and polyamide6-co-12 (PA6-12) were measured by pendant drop method. In the measurements for PA6-12 and EVOH of high ethylene contents, gamma 's were decreasing with elevating temperature. On the other hand, in the measurements for PA6-12 and EVOH of low ethylene contents, gamma 's were increasing with elevating temperature. On the basis of these results, interaction parameters, chi, were estimated. Resulting temperature dependence of chi parameters predicted a LCST phase behavior for the blends of PA6-12 and EVOH of low ethylene contents corresponding to our previous study.