Abstract
A model is developed for thermal oxidative degradation of polymer melts and its effect on their viscoelastic response. Based on the theory of temporary heterogeneous networks, stress-strain relations are derived for the time-dependent behavior of a polymer melt at arbitrary three-dimensional deformations with small strains. Within the fragmentation-annihilation concept, kinetic equation is proposed for the distribution of strands with various lengths in a network, and its explicit solution is obtained. Material parameters in the constitutive equations are found by fitting experimental data in shear oscillation tests on a polypropylene melt annealed at elevated temperatures for various times. Good agreement is demonstrated between the observations and the results of numerical simulation.
| Original language | English |
|---|---|
| Pages (from-to) | 882-904 |
| Number of pages | 23 |
| Journal | International Journal of Engineering Science |
| Volume | 45 |
| Issue number | 11 |
| DOIs | |
| State | Published - 1 Nov 2007 |
Keywords
- Fragmentation-annihilation
- Polypropylene
- Thermal oxidative degradation
- Viscoelasticity
ASJC Scopus subject areas
- Materials Science (all)
- Engineering (all)
- Mechanics of Materials
- Mechanical Engineering