Measurement of interfacial tension between polymer melts: Improved imbedded fiber retraction, breaking thread and dynamic viscoelasticity methods

Abstract

We improved the imbedded fiber retraction (IFR) method as a simple method to obtain the interfacial tension between polymer melts. A force balance equation for a fiber in an immiscible matrix by Cohen and Carriere is solved for a more realistic fiber shape at later stage of retraction. Moreover, unknown hydrodynamic coefficient in the balance equation is determined theoretically as 0.125. The interfacial tension between polystyrene (PS) and poly (methy methacrylate) (PMMA) is measured by the improved IFR (IIFR) method as well as the breaking thread method and dynamic viscoelasticity method. In dynamic viscoelasticity method, we determine the interfacial tension by fitting the Palierne theory with dynamic viscoelastic data. The interfacial tension obtained from the three methods agrees fairly well and is found to be about 1.6 mN m-1 at 180°C and 1.4 mN m-1 at 200°C.