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A Molecular Dynamics Study of Crosslinked Phthalonitrile Polymers: The Effect of Crosslink Density on Thermomechanical and Dielectric Properties

In this work, molecular dynamics (MD) and molecular mechanics (MM) simulations are used to study well-equilibrated models of 4,4′-bis(3,4-dicyanophenoxy)biphenyl (BPh)–1,3-bis(3-aminophenoxy)benzene (m-APB) phthalonitrile (PN) system with a range of crosslink densities. A cross-linking technique is...

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Autores principales: Chua, Janel, Tu, Qingsong
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6414959/
https://www.ncbi.nlm.nih.gov/pubmed/30966096
http://dx.doi.org/10.3390/polym10010064
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author Chua, Janel
Tu, Qingsong
author_facet Chua, Janel
Tu, Qingsong
author_sort Chua, Janel
collection PubMed
description In this work, molecular dynamics (MD) and molecular mechanics (MM) simulations are used to study well-equilibrated models of 4,4′-bis(3,4-dicyanophenoxy)biphenyl (BPh)–1,3-bis(3-aminophenoxy)benzene (m-APB) phthalonitrile (PN) system with a range of crosslink densities. A cross-linking technique is introduced to build a series of systems with different crosslink densities; several key properties of this material, including thermal expansion, mechanical properties and dielectric properties are studied and compared with experimental results. It is found that the coefficient of linear thermal expansion predicted by the model is in good agreement with experimental results and indicative of the good thermal stability of the PN polymeric system. The simulation also shows that this polymer has excellent mechanical property, whose strength increases with increasing crosslink density. Lastly and most importantly, the calculated dielectric constant—which shows that this polymer is an excellent insulating material—indicates that there is an inverse relation between cross-linking density and dielectric constant. The trend gave rise to an empirical quadratic function which can be used to predict the limits of attainable dielectric constant for highly crosslinked polymer systems. The current computational work provides strong evidence that this polymer is a promising material for aerospace applications and offers guidance for experimental studies of the effect of cross-linking density on the thermal, mechanical and dielectric properties of the material.
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spelling pubmed-64149592019-04-02 A Molecular Dynamics Study of Crosslinked Phthalonitrile Polymers: The Effect of Crosslink Density on Thermomechanical and Dielectric Properties Chua, Janel Tu, Qingsong Polymers (Basel) Article In this work, molecular dynamics (MD) and molecular mechanics (MM) simulations are used to study well-equilibrated models of 4,4′-bis(3,4-dicyanophenoxy)biphenyl (BPh)–1,3-bis(3-aminophenoxy)benzene (m-APB) phthalonitrile (PN) system with a range of crosslink densities. A cross-linking technique is introduced to build a series of systems with different crosslink densities; several key properties of this material, including thermal expansion, mechanical properties and dielectric properties are studied and compared with experimental results. It is found that the coefficient of linear thermal expansion predicted by the model is in good agreement with experimental results and indicative of the good thermal stability of the PN polymeric system. The simulation also shows that this polymer has excellent mechanical property, whose strength increases with increasing crosslink density. Lastly and most importantly, the calculated dielectric constant—which shows that this polymer is an excellent insulating material—indicates that there is an inverse relation between cross-linking density and dielectric constant. The trend gave rise to an empirical quadratic function which can be used to predict the limits of attainable dielectric constant for highly crosslinked polymer systems. The current computational work provides strong evidence that this polymer is a promising material for aerospace applications and offers guidance for experimental studies of the effect of cross-linking density on the thermal, mechanical and dielectric properties of the material. MDPI 2018-01-11 /pmc/articles/PMC6414959/ /pubmed/30966096 http://dx.doi.org/10.3390/polym10010064 Text en © 2018 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Chua, Janel
Tu, Qingsong
A Molecular Dynamics Study of Crosslinked Phthalonitrile Polymers: The Effect of Crosslink Density on Thermomechanical and Dielectric Properties
title A Molecular Dynamics Study of Crosslinked Phthalonitrile Polymers: The Effect of Crosslink Density on Thermomechanical and Dielectric Properties
title_full A Molecular Dynamics Study of Crosslinked Phthalonitrile Polymers: The Effect of Crosslink Density on Thermomechanical and Dielectric Properties
title_fullStr A Molecular Dynamics Study of Crosslinked Phthalonitrile Polymers: The Effect of Crosslink Density on Thermomechanical and Dielectric Properties
title_full_unstemmed A Molecular Dynamics Study of Crosslinked Phthalonitrile Polymers: The Effect of Crosslink Density on Thermomechanical and Dielectric Properties
title_short A Molecular Dynamics Study of Crosslinked Phthalonitrile Polymers: The Effect of Crosslink Density on Thermomechanical and Dielectric Properties
title_sort molecular dynamics study of crosslinked phthalonitrile polymers: the effect of crosslink density on thermomechanical and dielectric properties
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6414959/
https://www.ncbi.nlm.nih.gov/pubmed/30966096
http://dx.doi.org/10.3390/polym10010064
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AT tuqingsong moleculardynamicsstudyofcrosslinkedphthalonitrilepolymerstheeffectofcrosslinkdensityonthermomechanicalanddielectricproperties