Document Type

Article

Publication Date

4-2007

Abstract

In this work we attempt to answer several questions concerning the flow characteristics of entangled polymer solutions in a sliding plate shearing cell. We explore (a) how the molecular weight distribution affects the velocity profile in simple shear, (b) whether the observed shear banding is consistent with a nonmonotonic constitutive model, (c) whether the flow response and velocity profiles are different in simple shear depending on the different modes of shear. Our results provide a comparison with recent reports on a polydisperse polymer sample [Tapadia and Wang, Phys. Rev. Lett. 96, 016001 (2006); Tapadia, et al., Phys. Rev. Lett. 96, 196001 (2006)] that revealed the first evidence for inhomogeneous shear during startup in cone-plate flow geometry of a rotational rheometer. Using a highly monodisperse sample, we observed the sample to partition into two fractions with different local shear rates instead of possessing a smooth spatial variation of the local shear rate as seen for the polydisperse samples. In the stress plateau, the shear banding appears to involve various local shear rates instead of just two values. (c) 2007 The Society of Rheology.

Publication Title

Journal of Rheology

Volume

51

Issue

2

First Page

217

Last Page

233

Required Publisher's Statement

Copyright 2007 American Institute of Physics. The original published version of this article may be found at http://dx.doi.org/10.1122/1.2424947.

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