Measurement of interfacial tension between polymer liquids : Pendant drop, improved imbedded fiber retraction and steady shear flow methods

Abstract

The interfacial tension between a poly (isobutylene) (PIB) and a poly (dimethylsiloxane) (PDMS) was obtained by an improved imbedded fiber retraction method from the observation of the PDMS (or PIB) droplet shape in the PIB (or PDMS) matrix after application of the step shear strain. The interfacial tension was also obtained from the observation of the PDMS (or PIB) droplet shape during the steady shear flow. We compared the values of interfacial tension obtained by these methods with the value determined by the pendant drop method. It was found that these values agree fairly well when the viscosity ratio of the droplet to the matrix is around unity.