Effect of Interfacial Tension on the Structure and Properties of Polymer Blends

Abstract

Effect of interfacial tension on the structure and mechanical properties of molten immiscible polymer blends has been studied. Following a rheological constitutive equation proposed by Palierne, the interfacial tension is estimated from the viscoelastic properties. In this paper, the values of interfacial tension for various kinds of polyolefin pairs are summarized. The interfacial tension is responsible for the phase separated structure of immiscible polymer blends. The size of the dispersed phase decreases with decreasing the interfacial tension. Moreover, adding a compatibilizer that is a block or graft copolymer of an immiscible polymer pair exerts a significant influence on the structure of the blend. Locating between the different phases, the compatibilizer prevents disperse particles from coalescing together during the mixing process and, as a result, the size of particles decreases.