Prediction of the minor phase size in immiscible polymer blends

Abstract

The influence of the composition on the drop size of the minor phase in immiscible polymer blends was studied. The mixtures were prepared using an internal mixer chamber (Haake). The systems analyzed were: PA6/HPDE, PS/HDPE, PA6/PS, PC/HPDE and PC/PP. A morphological study was made in order to obtain the average drop size as a function of the composition. The Tokita's theory was used to predict the drop size of the minor phase. This theory is based on the balance between deformation and coalescence process. The model includes rheological and interfacial parameters, such as shear stress (τ21), interfacial tension (ν), bulk breaking energy (Edk). In order to produce a deformation of the minor phase, it is required that τ21≫Edk. However, the Edk value calculated from experimental result show that Edk≈τ21.