Relaxation times in deformed polymer glasses: {A} comparison between molecular simulations and two theories

Publication Type
Journal Article
Year of Publication
2016
Authors
Rottler, Jörg
Name of Publication
The Journal of Chemical Physics
Volume
145
Pagination
064505
ISSN
0021-9606, 1089-7690
Keywords
creep, Glasses, molecular dynamics, Relaxation times, shear deformation
Abstract

Relaxation times in polymer glasses are computed with molecular dynamics simulations of a coarse-grained polymer model during creep and constant strain rate deformation. The dynamics is governed by a competition between physical aging that increases relaxation times and applied load or strain rate which accelerates dynamics. We compare the simulation results quantitatively to two recently developed theories of polymer deformation, which treat aging and rejuvenation in an additive manner. Through stress release and strain rate reversal simulations, we then show that the quantity governing mechanical rejuvenation is the rate of irreversible work performed on the polymer.