article

Abstract

A model was developed to describe phase continuity in immiscible blends based on the geometrical requirements for co-continuous structures. The minor phase is considered to be an assembly of randomly oriented rods touching each other at their maximum packing density. The model results from the relation between this density and the aspect ratio of these phases, in conjunction with the microrheological requirements for the existence and stability of long-shaped phases in the flow field of a mixer. This model gives the critical volume fraction of the minor phase for complete continuity as a function of the matrix viscosity, the interfacial tension, the shear rate and the phase dimensions. Experimental results of blends of PS and PE show that the model quantitatively predicts the trends in the critical volume fraction for co-continuity when the viscosities of the phases change.

Polymer, 39, 5879-5887, 1998

Co-continuous morphologies in polymer melts: a new model