Nonlinear mechanics of triblock copolymer elastomers: from molecular simulations to network models

TL;DR

This paper develops a molecularly-informed network model for triblock copolymer elastomers that accurately predicts their nonlinear stress response using minimal parameters, bridging molecular simulations and macroscopic behavior.

Contribution

It introduces a novel entropic network model that integrates microscopic chain conformations with macroscopic stress predictions for copolymer elastomers.

Findings

Model accurately predicts stress response from molecular data.

Only one elastic modulus needed for different network types.

Quantitative agreement with experimental and simulation data.

Abstract

We introduce an entropic network model for copolymer elastomers based on the evolution of microscopic chain conformations during deformation. We show that the stress results from additive contributions due to chain stretch at the global as well as entanglement level. When these parameters are computed with molecular simulations, the theory quantitatively predicts the macroscopic stress response. The model requires only one elastic modulus to describe both physically crosslinked triblock networks and uncrosslinked homopolymers.