Electroactive shaping and shape memory of sequential dual-cured off-stoichiometric epoxy/CNT composites
| Autor: | C.G. Díaz-Maroto, A. Jiménez-Suárez, S.G. Prolongo |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Materials science
Carbon nanotubes Carbon nanotube law.invention Biomaterials Epoxy nanocomposite law Composite material Curing (chemistry) Nanocomposite Mining engineering. Metallurgy Metals and Alloys TN1-997 Joule heating Shape-memory alloy Epoxy Dynamic mechanical analysis Surfaces Coatings and Films Shape memory visual_art Ceramics and Composites visual_art.visual_art_medium Glass transition Sequential dual curing |
| Zdroj: | Journal of Materials Research and Technology, Vol 15, Iss, Pp 2970-2981 (2021) BURJC-Digital. Repositorio Institucional de la Universidad Rey Juan Carlos instname |
| ISSN: | 2238-7854 |
| Popis: | Sequential dual-cured epoxy composites, based on off-stoichiometric thiol–epoxy mixtures catalysed by 1-methylimidazole, have been developed by adding carbon nanotubes (CNT). The epoxy curing process initially consists in two thermally activated curing stages: a first thiol–epoxy reaction and later homopolymerization at a higher temperature. This system presents easy shaping/conforming and shape memory properties through thermo-mechanical treatments. Addition of the electrical CNT network into the epoxy matrix allows electrical switching, which increases its performance and in-situ applicability. The obtained results confirmed that CNTs catalyse the homopolymerization epoxy reaction, hindering the sequential curing process, due to the π–π anchoring of imidazole catalyser over the CNTs surface, enhanced by donor–acceptor interaction. Non-doped off-stoichiometric resins present relatively high thermal strength, with a glass transition temperature in the range of 73–109 °C, and high stiffness, with a storage modulus close to 2–3 GPa. They can be easily conformed at low temperature, 60 °C, before their second curing stage, showing a high shaping efficiency (around 90%) and full fixing efficiency (>98%). Nanocomposites with 0.2% CNT present efficient Joule heating, triggering the shape memory at low voltage |
| Databáze: | OpenAIRE |
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