A model for filler—matrix debonding in glass-bead-filled viscoelastic polymers

✍ Scribed by A. Meddad; B. Fisa

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 298 KB
• Volume: 65
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19970906)65:10<2013::aid-app19>3.0.co;2-6

✦ Synopsis

This article deals with the stress-strain behavior of two viscoelastic polymers, polypropylene and polyamide 6, filled with rigid particles in the range of axial strain of 0 to 8%. These materials, when subjected to a constant strain rate test lose stiffness via two mechanisms: filler-matrix debonding and the viscoelastic softening of the matrix. A model that combines the concepts of damage mechanics and the time dependence of the interfacial strength is described and compared to the experimental results of polypropylene and polyamide 6 filled with up to 50 vol % of untreated and silane-treated glass beads. The matrix behavior is described in terms of an empirical equation selected to fit the stress-strain behavior of neat polymers in the range of strain rates between 0.12 and 0.5% s 01 and strains between 0 and 8%. The stiffness of the damaged, partially debonded composite is calculated using the Kerner-Lewis equation assuming that debonded particles do not bear any load. The model is able to generate stress-strain curves that are in good agreement with the experimental data. The void volume attributable to debonding calculated using the model is much smaller than the experimental total determined void volume (which is a sum of several deformation mechanisms).