THE EFFECT OF TEMPERATURE ON THE INTERFACIAL-TENSION OF POLYCARBONATEPOLYETHYLENE BLENDS/

Controlling interfacial tension during the processing of blends is cri tical to developing morphologies that will yield consistent and accept able mechanical properties. Determination of the interfacial tension i s important in developing a predictive understanding of the effects of processing conditions on the morphology and the physical properties o f multicomponent systems. The focus of the research reported herein wa s to investigate the temperature dependence of the interfacial tension for blends composed of polycarbonate (PC) and polyethylene (PE). The effects of temperature were characterized by direct measurements of th e interfacial tension using the imbedded fiber retraction (IFR) method . The interfacial tensions of PC/PE were measured at 210, 220, 230, an d 240 degrees C. The temperature dependence of the interfacial tension was found to be -0.018 +/- 0.006 dyn/cm-degrees C. In general, the in terfacial tension, evaluated for low-viscosity simple fluids, is commo nly a weak function of temperature (on the order of 0.01 dyn/cm-degree s C). The results found in this study are in accord with those finding s.