Polydisperse polymer networks with irregular topologies I: Mechanics of cross-link distributions

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Mulderrig, Jason, Buche, Michael, Grasinger, Matthew
Natura: Preprint
Pubblicazione: 2025
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866918388480081920
author Mulderrig, Jason
Buche, Michael
Grasinger, Matthew
author_facet Mulderrig, Jason
Buche, Michael
Grasinger, Matthew
contents The structure of polymer networks, defined by chain lengths and connectivity patterns, fundamentally influences their bulk properties. While existing polymer network models connect chain properties to emergent network behavior, they are often limited to monodisperse networks with regular connectivities. In this work, we introduce a novel modeling framework that shifts the focus from individual polymer chains to cross-links and their connected chains as the fundamental unit of analysis. The key features of this framework are the relaxation of the cross-link junction position to satisfy local force balance, and physically intuitive means for satisfying material frame indifference. We explore two distinct limiting behaviors for the orientation of the frame of a cross-link: (1) the free rotation limit, which assumes the cross-link rotates to minimize free energy, and (2) the frame averaging limit, which incorporates structural heterogeneity by averaging over all possible cross-link orientations. It is found that an increase in variance in monomer numbers generally leads to network softening, while in bimodal networks, the onset of strain stiffening is controlled by shorter chains and the stiffening response is modulated by the ratio of short to long chains. By deriving closed-form approximations for both limits valid in the regimes of small deformation or small polydispersity, we offer an efficient computational approach to modeling the mechanics of complex, polydisperse networks. An aim of this framework is to take a step toward the rational modeling and design of heterogeneous polymer networks with structures tailored for specific properties.
format Preprint
id arxiv_https___arxiv_org_abs_2504_17239
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Polydisperse polymer networks with irregular topologies I: Mechanics of cross-link distributions
Mulderrig, Jason
Buche, Michael
Grasinger, Matthew
Soft Condensed Matter
The structure of polymer networks, defined by chain lengths and connectivity patterns, fundamentally influences their bulk properties. While existing polymer network models connect chain properties to emergent network behavior, they are often limited to monodisperse networks with regular connectivities. In this work, we introduce a novel modeling framework that shifts the focus from individual polymer chains to cross-links and their connected chains as the fundamental unit of analysis. The key features of this framework are the relaxation of the cross-link junction position to satisfy local force balance, and physically intuitive means for satisfying material frame indifference. We explore two distinct limiting behaviors for the orientation of the frame of a cross-link: (1) the free rotation limit, which assumes the cross-link rotates to minimize free energy, and (2) the frame averaging limit, which incorporates structural heterogeneity by averaging over all possible cross-link orientations. It is found that an increase in variance in monomer numbers generally leads to network softening, while in bimodal networks, the onset of strain stiffening is controlled by shorter chains and the stiffening response is modulated by the ratio of short to long chains. By deriving closed-form approximations for both limits valid in the regimes of small deformation or small polydispersity, we offer an efficient computational approach to modeling the mechanics of complex, polydisperse networks. An aim of this framework is to take a step toward the rational modeling and design of heterogeneous polymer networks with structures tailored for specific properties.
title Polydisperse polymer networks with irregular topologies I: Mechanics of cross-link distributions
topic Soft Condensed Matter
url https://arxiv.org/abs/2504.17239