Transient rheology of a polyethylene melt under shear
Using nonequilibrium molecular dynamics simulation, we have studied the response of a C100 model polymer melt to a step change from equilibrium to a constant, high shear rate flow. The transient shear stress of the model polymer melt exhibits pronounced overshoot at the strain value predicted by the...
| Veröffentlicht in: | Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics. - 1993. - 60(1999), 6 Pt B vom: 30. Dez., Seite 6956-9 |
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| Weitere Verfasser: | , , |
| Format: | Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
1999
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| Zugriff auf das übergeordnete Werk: | Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics |
| Schlagworte: | Journal Article |
| Zusammenfassung: | Using nonequilibrium molecular dynamics simulation, we have studied the response of a C100 model polymer melt to a step change from equilibrium to a constant, high shear rate flow. The transient shear stress of the model polymer melt exhibits pronounced overshoot at the strain value predicted by the reptation model, in striking similarity to melts of longer, entangled polymer governed by reptation motion. At the maximum of shear stress overshoot, the molecular orientational order and the alignment angle are found to be midway between those characteristic of Newtonian flow and full alignment with the flow. The Doi-Edwards theory is found to be applicable but only by taking into account the shear-rate-dependence of the terminal relaxation time. We further analyze the molecular origins of such behavior in short polymer chains by decomposing the total stress into the contributions from various molecular interactions |
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| Beschreibung: | Date Completed 09.08.2002 Date Revised 28.07.2019 published: Print Citation Status PubMed-not-MEDLINE |
| ISSN: | 1063-651X |