Are Polymer Melts Visco‐Anelastic?

Abstract

We raise the question: should polymer melts be described in the usual way as materials that dissipate stress and elastic energy only by gradual relaxation, or are they better described as able to dissipate some stress and elastic energy virtually instantaneously? That is, can they be better described as having relaxing anelasticity? We show that an anelastic description has molecular underpinnings in the tube theory of Doi, has precedent in the empirical constitutive model of Wagner, and has experimental support, both in previous literature on strain recovery, and in data presented here on reversing double‐step shear straining of a linear low density polyethylene.