Elasticity and Plasticity in Stiff and Flexible Oligomeric Glasses

TL;DR

This paper investigates the mechanical behavior of oligomeric glasses through simulations and theory, focusing on shear modulus, failure mechanisms, and geometric responses of oligomers under stress.

Contribution

It introduces a microscopic theory that explains shear modulus, plastic instabilities, and geometric changes in oligomeric glasses, supported by numerical simulations.

Findings

Exact theory of shear modulus and plastic instabilities

Identification of local and system-spanning failure mechanisms

Model explaining geometric changes in oligomer chains

Abstract

In this paper we focus on the mechanical properties of oligomeric glasses (waxes), employing a microscopic model that provides, via numerical simulations, information about the shear modulus of such materials, the failure mechanism via plastic instabilities and about the geometric responses of the oligomers themselves to a mechanical load. We present a microscopic theory that explains the numerically observed phenomena, including an exact theory of the shear modulus and of the plastic instabilities, both local and system spanning. In addition we present a model to explain the geometric changes in the oligomeric chains under increasing strains.