Curvature-driven shear banding in polymer melts

We consider a melt of two chemically identical homopolymers of different lengths. Both species obey Rouse dynamics, and always form a homogeneous mixture at equilibrium. Under shear flow in a wide-gap Couette, such a system exhibits strongly inhomogeneous steady states, that resemble macro-phase separated blends. The corresponding velocity profile is nonmonotonic and exhibits distinct shear bands. These findings may have implications for the processing of polydisperse polymer melts. (C) 1999 The Society of Rheology. [S0148-6055(99)00805-6].