Dynamics of Phase Behavior of a Polymer Blend Under Shear Flow

TL;DR

This paper investigates how shear flow influences the phase behavior of polymer blends by developing kinetic equations and highlighting the importance of shear modulus dependence on composition for stability shifts.

Contribution

It introduces a kinetic model for polymer blends under shear flow using a two-fluid approach and a generalized material derivative.

Findings

Shear flow can induce stability shifts in polymer blends.

Nonlinear shear modulus dependence on composition is crucial.

A generalized kinetic framework for phase behavior under flow.

Abstract

We study the dynamics of the phase behavior of a polymer blend in the presence of shear flow. By adopting a two fluid picture and using a generalization of the concept of material derivative, we construct kinetic equations that describe the phase behavior of polymer blends in the presence of external flow. A phenomenological form for the shear modulus for the blend is proposed. The study indicates that a nonlinear dependence of the shear modulus of the blend on the volume fraction of one of the species is crucial for a shift in the stability line to be induced by shear flow.