Non-equilibrium relaxation law for entangled polymers

Abstract

We study the far-from-equilibrium relaxation of an initially stretched, entangled polymer by using an exactly solvable lattice gas model for reptation. Over a significant time range, including an initial universal power law regime, the predicted tube length relaxation is in very good agreement with experimental data for the relaxation of DNA. Experimental evidence and theoretical arguments suggest an observed systematic long-time deviation to be due to entanglement fluctuations. This view is confirmed by the analysis of an extension of the lattice gas model which appears to be a reliable foundation for further study of reptation dynamics.