Nikiforidis, V.-M.; Tsalikis, D.G.; Stephanou, P.S. On The Use of a Non-Constant Non-Affine or Slip Parameter in Polymer Rheology Constitutive Modeling. Dynamics2022, 2, 380-398.
Nikiforidis, V.-M.; Tsalikis, D.G.; Stephanou, P.S. On The Use of a Non-Constant Non-Affine or Slip Parameter in Polymer Rheology Constitutive Modeling. Dynamics 2022, 2, 380-398.
Nikiforidis, V.-M.; Tsalikis, D.G.; Stephanou, P.S. On The Use of a Non-Constant Non-Affine or Slip Parameter in Polymer Rheology Constitutive Modeling. Dynamics2022, 2, 380-398.
Nikiforidis, V.-M.; Tsalikis, D.G.; Stephanou, P.S. On The Use of a Non-Constant Non-Affine or Slip Parameter in Polymer Rheology Constitutive Modeling. Dynamics 2022, 2, 380-398.
Abstract
Since its introduction, back in the late 1970s, the non-affine or slip parameter, ξ, has been routinely employed by numerous constitutive models as a constant parameter. However, the evidence seems to imply that it should be a function of polymer deformation. In the present work, we phenomenologically modify a constitutive model for the rheology of unentangled polymer melts [P. S. Stephanou et al. J. Rheol. 53, 309 (2009)] to account for a non-constant slip parameter. The revised model predictions are compared against newly accumulated rheological data for a C48 polyethylene melt obtained via direct non-equilibrium molecular dynamics simulations in shear. We find that the conformation tensor data are very well predicted; however, the predictions of the material functions are noted to deviate from the NEMD data, especially at large shear rates.
Chemistry and Materials Science, Polymers and Plastics
Copyright:
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