Beyond the ring flip: A molecular signature of the glass–rubber transition in tetrafunctional epoxy resins
| Autor: | Russell J. Varley, Larry Q. Reyes, Samuel R. Swan, Tiffany R. Walsh, Filip Vuković |
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| Rok vydání: | 2020 |
| Předmět: |
Yield (engineering)
Materials science Polymers and Plastics Ring flip Organic Chemistry 02 engineering and technology Epoxy 010402 general chemistry 021001 nanoscience & nanotechnology Ring (chemistry) 01 natural sciences 0104 chemical sciences Molecular dynamics Natural rubber visual_art Thermal Materials Chemistry visual_art.visual_art_medium Composite material 0210 nano-technology Glass transition |
| Zdroj: | Polymer. 206:122893 |
| ISSN: | 0032-3861 |
| Popis: | The glass–rubber structural transition of epoxy resins is a critical quantity in the design of resins for thermally demanding applications. Currently, many high T g epoxy resins exhibit reduced mechanical performance and are not suitable for structural applications. A present lack of understanding regarding the molecular origins of the glass–rubber transition, together with the cost of resin synthesis, has limited progress in the targeted development of novel, mechanically strong, high- T g resins. Here, molecular dynamics simulations are used to predict the molecular-level structure and thermo-mechanical properties of three tetrafunctional epoxy resins. Via introduction of a conceptual framework of monitoring local molecular motions during molecular dynamics simulations, a characteristic molecular signature of segmental dynamics, correlating with the glass transition temperature, is identified. This computational framework provides a cost-effective strategy for rapidly assessing the comparative thermal performance of novel epoxy resins. Additionally, the impact of ring substitution on the thermo-mechanical properties of the naphthalene-based resins reveals promising directions for future design to yield desirable mechanical and thermal properties. |
| Databáze: | OpenAIRE |
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