Effects of Epoxy Composition on the Thermal and Network Properties of Crosslinked Thermosets: A Molecular-Dynamics Study

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Pola, Venkata Rama Manoj, Lyulin, Alexey
Natura: Preprint
Pubblicazione: 2025
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866911058111758336
author Pola, Venkata Rama Manoj
Lyulin, Alexey
author_facet Pola, Venkata Rama Manoj
Lyulin, Alexey
contents In this study, we investigate the influence of resin composition on the thermal and structural properties of crosslinked epoxy networks using molecular-dynamics simulations. The systems studied are based on mixtures of diglycidyl ether of bisphenol A (DGEBA) and butylated epoxy resin (BER), cured with diethyltoluenediamine (DETDA). A multi-step crosslinking algorithm was used to generate highly crosslinked networks. We systematically explored how the addition of BER affects the network topology and thermophysical behavior of the resulting thermosets. Our results show that increasing BER content leads to a progressive loosening of the network, evidenced by longer inter-nitrogen path lengths and larger Voronoi atomic volumes. This structural loosening results in a higher coefficient of thermal expansion (CTE) and higher atomic mobility as well as a reduction in the glass-transition temperature. To quantify local steric and topological effects, we introduce a confinement index that captures atomic-level crowding and connectivity. The index shows a strong correlation with the observed trend in glass-transition temperature, suggesting its potential as a predictive descriptor for polymer network behavior. Our findings provide molecular-level insights into how epoxy resin composition modulates network structure and thermomechanical properties.
format Preprint
id arxiv_https___arxiv_org_abs_2507_11453
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Effects of Epoxy Composition on the Thermal and Network Properties of Crosslinked Thermosets: A Molecular-Dynamics Study
Pola, Venkata Rama Manoj
Lyulin, Alexey
Soft Condensed Matter
Materials Science
In this study, we investigate the influence of resin composition on the thermal and structural properties of crosslinked epoxy networks using molecular-dynamics simulations. The systems studied are based on mixtures of diglycidyl ether of bisphenol A (DGEBA) and butylated epoxy resin (BER), cured with diethyltoluenediamine (DETDA). A multi-step crosslinking algorithm was used to generate highly crosslinked networks. We systematically explored how the addition of BER affects the network topology and thermophysical behavior of the resulting thermosets. Our results show that increasing BER content leads to a progressive loosening of the network, evidenced by longer inter-nitrogen path lengths and larger Voronoi atomic volumes. This structural loosening results in a higher coefficient of thermal expansion (CTE) and higher atomic mobility as well as a reduction in the glass-transition temperature. To quantify local steric and topological effects, we introduce a confinement index that captures atomic-level crowding and connectivity. The index shows a strong correlation with the observed trend in glass-transition temperature, suggesting its potential as a predictive descriptor for polymer network behavior. Our findings provide molecular-level insights into how epoxy resin composition modulates network structure and thermomechanical properties.
title Effects of Epoxy Composition on the Thermal and Network Properties of Crosslinked Thermosets: A Molecular-Dynamics Study
topic Soft Condensed Matter
Materials Science
url https://arxiv.org/abs/2507.11453