Dresden 2011 – scientific programme

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 43: Nanoparticles and Composite Materials I

CPP 43.2: Talk

Thursday, March 17, 2011, 14:30–14:45, ZEU 222

Modelling of stress and strain amplification effects in filled polymer melts — •Jan Domurath, Marina Saphiannikova, and Gert Heinrich — Leibniz-Institut für Polymerforschung Dresden e.V., Hohe Strasse 6, 01069 Dresden

When hard filler particles are added to a polymer melt, it is usually assumed that it’s zero-shear viscosity and therefore the stress increase according to Einstein’s or a similar formula. In some papers one finds an alternative approach in which the local strain field is increased according to these formulas. Although both approaches provide the same increase of the shear stress in the linear limit, it can be shown that the second approach violates the energy conservation law as the macroscopic and microscopic dissipated energies are not equal anymore. In this contribution we propose a new stress and strain amplification approach in which both the stress and strain tensors are modified to describe the behaviour of filled polymer melts in the non-linear shearing regime. The new approach is tested using relatively simple constitutive models for description of nonlinear viscoelastic behaviour in polymer melts. The stress and strain amplification approach enables us to explain the peculiar behaviour of the overshoot peak observed recently in filled LDPE melts [1].
F.R. Costa et al. Adv. Polym. Sci. 210, 101 (2008)