On the physical basis for the nematic rubber elastic free energy

TL;DR

This paper explores the physical justification for including order parameter-dependent terms in the free energy of nematic rubber elasticity, addressing mathematical difficulties in existing models.

Contribution

It clarifies the importance of natural size dependence on the order parameter in nematic rubber free energy formulations, resolving a key mathematical issue.

Findings

Including order parameter dependence is physically justified.

Addresses and resolves a mathematical difficulty in existing models.

Highlights the significance of natural size variations in nematic rubber elasticity.

Abstract

We discuss why it is physical to keep terms in the nematic rubber elastic free energy that reflect the order parameter dependence of the natural size of the network polymers. We address a point of difficulty in some mathematical approaches to this problem.