Using Multiple-Mode Models for Fitting and Predicting the Rheological Properties of Polymeric Melts. Part II. Single and Double Step- Strain Flows
Several classes of multiple-mode rheological constitutive equations are examined for predicting the viscoelastic flow properties of a typical polymer melt in single and double step-strain flows. The phenomenological parameters appearing in these models have been obtained by the fitting of experimental data taken in small-amplitude oscillatory shear and steady shear flows. The performance of the models for predicting the experimental data in the step-strain experiments is examined in detail. Specifically, we examine whether or not mode coupling is necessary to describe the experimental behavior under step-strain flows. Furthermore, it is demonstrated that the reversing double step-strain experiment is a very powerful tool for testing viscoelastic constitutive equations.
AU: B. Jiang AU: P. A. Kamerkar AU: D. J. Keffer AU: B. J. Edwards TI: Using multiple-mode models for fitting and predicting the rheological properties of polymeric melts. II. Single and double step-strain flows SO: Journal of Applied Polymer Science VL: 105 NO: 5 PG: 2884-2892 YR: 2007 CP: Copyright © 2007 Wiley Periodicals, Inc. ON: 1097-4628 PN: 0021-8995 AD: Department of Chemical Engineering, University of Tennessee, Knoxville, Tennessee 37996-2200 DOI: 10.1002/app.26334 US: http://dx.doi.org/10.1002/app.26334