A Monte Carlo Simulation Study of the Mechanical and Conformational Properties of Networks of Helical Polymers. I General Concepts

TL;DR

This study uses Monte Carlo simulations and the Three-chain Model to explore the unique non-monotonic stress-strain behavior of helical polymer networks, revealing the role of helix formation and melting in their mechanical response.

Contribution

It introduces a combined simulation and modeling approach to analyze the mechanical and conformational properties of helical polymer networks, highlighting novel non-monotonic stress behavior.

Findings

Networks exhibit initial strengthening, then softening, then strengthening again under stretch.

Stress behavior correlates with changes in helical content due to elongation.

Molecular mechanisms involve formation and melting of helical structures.

Abstract

We study the mechanical and conformational properties of networks of helical polymers with a combination of Monte Carlo simulations based on the Wang-Landau algorithm and the Three-chain Model. We find that the stress-strain behavior of these networks has novel features not observed in typical networks made of synthetic polymers. In particular, we find that as these networks are stretched they first strengthen, then soften and finally strengthen again. This non-monotonic behavior of the stress correlates with the one of the helical content and is rationalized by the elongation-induced formation and melting of the helical structure of the polymer. We complement these results with a study of other conformational properties of the polymer strands that clarify the molecular mechanisms behind the mechanical behavior of these networks. Finally, we present a qualitative comparison of some of our results with the theoretical ones recently reported by Kutter and Terentjev.