Melt viscosities of lattice polymers using a Kramers potential treatment

Abstract

Kramers relaxation times ${\tau }_K$ and relaxation times ${\tau }_R$ and ${\tau }_G$ for the end-to-end distances and for center of mass diffusion are calculated for dense systems of athermal lattice chains. ${\tau }_K$ is defined from the response of the radius of gyration to a Kramers potential which approximately describes the effect of a stationary shear flow. It is shown that within an intermediate range of chain lengths N the relaxation times ${\tau }_R$ and ${\tau }_K$ exhibit the same scaling with N, suggesting that N-dependent melt-viscosities for non-entangled chains can be obtained from the Kramers equilibrium concept.

arXiv commentsubmitted to: Journal of Chemical Physics