Dissertation
Effect of network topology on thermoset material thermo-mechanical properties: a molecular simulation study
Doctor of Philosophy (Ph.D.), Drexel University
Jun 2022
DOI:
https://doi.org/10.17918/00001155
Abstract
Thermosetting polymers are one of the materials used in additive manufacturing which can be used to construct objects with superior thermo-mechanical properties. Understanding the structure-property relationship of thermosetting polymers can allow controlling of materials' thermo-mechanical properties. Molecular Dynamics (MD) simulations is a powerful tool which can be used to predict the thermo-mechanical properties of a given atomistic molecular structure. And it can provide an insight of the molecular level topology of the molecular system which is sometimes difficult for experiments to obtain. This dissertation presents the computational methods for estimating the thermo-mechanical properties of thermosetting polymers. A general framework for constructing the models of fully cured amorphous polymers is proposed. This framework, which termed HTPolyNet, has been validated through various cases including the linear and network polymers. With the help of HTPolyNet, we construct a series vinyl ester (VE) resins network topololgies which have similar molecular weight between crosslinks (Mc) as experiment networks which cured at different temperature. The MD simulation results show the glass transition temperature (Tg) and glassy youngs modulus E are not sensitive with the Mc. Additionally, we measured the E within a wider time and temperature range. Using the time-temperature superposition principle, we built the connection between simulation and experiment E. Importantly, the results revealed the E at high temperatures does depend on network topology. Lastly, We studied the structure-properties relations on an epoxy resin systems (FDE). Modification on the furan rings on the hardener molecules are presented, and a systematic study on how these modifications affect the system's thermo-mechanical properties are discussed. This dissertation demonstrates that MD simulation can be used to predict the thermo-mechanical properties and studied the structure-properties relation of the thermosetting polymer system in a much wider time and length scale than the experiments. Furthermore, MD simulations provide the analysis on the inter- and intramolecular interactions, which is challenge to obtain from the experiments. This analysis may help researchers on designing the thermosetting polymer with desired properties.
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Details
- Title
- Effect of network topology on thermoset material thermo-mechanical properties
- Creators
- Ming Huang
- Contributors
- Cameron F. Abrams (Advisor)
- Awarding Institution
- Drexel University
- Degree Awarded
- Doctor of Philosophy (Ph.D.)
- Publisher
- Drexel University; Philadelphia, Pennsylvania
- Number of pages
- xv, 125 pages
- Resource Type
- Dissertation
- Language
- English
- Academic Unit
- Chemical (and Biological) Engineering (1970-2026); College of Engineering (1970-2026); Drexel University
- Other Identifier
- 991018526908604721