Thermalization of plastic flow versus stationarity of thermomechanical equilibrium in SGR theory

TL;DR

This paper examines the challenge of modeling thermally equilibrated plastic flow within the soft glassy rheology framework, highlighting the need for a theory that accurately captures thermalization in small-molecule and polymer glasses.

Contribution

It identifies the limitations of current SGR theory regarding thermalized plastic flow and discusses the conceptual obstacles to developing a more comprehensive model.

Findings

Current SGR theory implies athermal plastic flow for stationarity.

Thermalized plastic flow is essential for accurately modeling polymer glasses.

The paper outlines key challenges in extending SGR to include thermalization.

Abstract

We discuss issues related to thermalization of plastic flow in the context of soft glassy rheology (SGR) theory. An apparent problem with the theory in its current form is that the stationarity of thermomechanical equilibrium obtained by requiring that its flow rule satisfy detailed balance in the absence of applied deformation requires plastic flow to be athermal. This prevents proper application of SGR to small-molecule and polymer glasses where plastic flow is often well-thermalized. Clearly, one would like to have a SGR-like theory of thermalized plastic flow that satisfies stationarity. We discuss reasons why such a theory could prove very useful and clarify obstacles that must be overcome in order to develop it.