A molecular based model for polymer viscoelasticity: Intra- and inter-molecular variability
| Autor: | Negash G. Medhin, Harvey Thomas Banks, Jeffrey B. Hood |
|---|---|
| Rok vydání: | 2008 |
| Předmět: |
chemistry.chemical_classification
Materials science Applied Mathematics Relaxation (NMR) Mechanics Polymer Viscoelasticity Reptation Molecular dynamics chemistry Natural rubber Modeling and Simulation visual_art Modelling and Simulation Calculus visual_art.visual_art_medium Molecule Internal variable |
| Zdroj: | Applied Mathematical Modelling. 32(12):2753-2767 |
| ISSN: | 0307-904X |
| DOI: | 10.1016/j.apm.2007.09.018 |
| Popis: | We develop dynamic equations for rubber viscoelasticity based on a stick-slip continuum molecular-based model. The model developed is a continuum tube reptation model in which a chemically cross-linked (CC) system of molecules act as constraint box per unit volume for a physically constrained (PC) system of molecules. The CC-system carries along the PC-system during instantaneous step deformations. The subsequent relaxation of the PC-system is determined by the configuration of the CC-system, its own configuration and confirmation, and external force fields. Conversely, the deformation of the PC-system acts as an internal variable affecting the deformations of the constraining CC-system. We model the relationship between these processes to derive a model of viscoelasticity in rubber deformation. In developing a relaxation process for the PC-system, we start from the fact that the PC-system is composed of long molecular chains. The dynamics of these molecular chains are developed by modelling them as chains of beads connected by springs, which represent inter-molecular potentials. Various segments of the molecular chains relax at different rates. In addition, variability in relaxation times across molecular chains is permitted. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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