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Study on Curing Kinetics and the Mechanism of Ultrasonic Curing of an Epoxy Adhesive
Ultrasonic curing is an effective way to enhance the curing extent of composite material bonding in the aerospace industry. The non-thermal effect of ultrasonic has been revealed to improve curing efficiency. However, the mechanism of the ultrasonic non-thermal effect is still not clear. In this wor...
Autores principales: | , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2022
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8840220/ https://www.ncbi.nlm.nih.gov/pubmed/35160500 http://dx.doi.org/10.3390/polym14030512 |
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author | Liu, Zhaoyi Wang, Hui Chen, Yizhe Kang, Guodong Hua, Lin Feng, Jindong |
author_facet | Liu, Zhaoyi Wang, Hui Chen, Yizhe Kang, Guodong Hua, Lin Feng, Jindong |
author_sort | Liu, Zhaoyi |
collection | PubMed |
description | Ultrasonic curing is an effective way to enhance the curing extent of composite material bonding in the aerospace industry. The non-thermal effect of ultrasonic has been revealed to improve curing efficiency. However, the mechanism of the ultrasonic non-thermal effect is still not clear. In this work, a variable activation energy model of ultrasonic curing was established by utilizing the iso-conversional method, including the activation energy of the thermal effect and activation energy of the non-thermal effect. The thermal effect caused by ultrasonic was accurately peeled off. An obvious decrease in activation energy was found from 54 kJ/mol in thermal curing to 38 kJ/mol in ultrasonic curing. The activation energy of the reaction system in ultrasonic curing was substituted into the modified Kamal autocatalytic equation, and the parameters of the ultrasonic curing kinetic model were estimated by means of an ALO algorithm. Further discussion based on in situ FTIR showed that the non-thermal effect of ultrasonic can affect the vibration strength, stability, and chemical bond energy of internal groups, but cannot cause the fracture of chemical bonds. Moreover, frontier molecular orbital analysis showed that the chemical reactivity of epoxy/amine molecules increased and the HOMO–LUMO energy gap decreased from 6.511 eV to 5.617 eV under the effect of ultrasonic. |
format | Online Article Text |
id | pubmed-8840220 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2022 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-88402202022-02-13 Study on Curing Kinetics and the Mechanism of Ultrasonic Curing of an Epoxy Adhesive Liu, Zhaoyi Wang, Hui Chen, Yizhe Kang, Guodong Hua, Lin Feng, Jindong Polymers (Basel) Article Ultrasonic curing is an effective way to enhance the curing extent of composite material bonding in the aerospace industry. The non-thermal effect of ultrasonic has been revealed to improve curing efficiency. However, the mechanism of the ultrasonic non-thermal effect is still not clear. In this work, a variable activation energy model of ultrasonic curing was established by utilizing the iso-conversional method, including the activation energy of the thermal effect and activation energy of the non-thermal effect. The thermal effect caused by ultrasonic was accurately peeled off. An obvious decrease in activation energy was found from 54 kJ/mol in thermal curing to 38 kJ/mol in ultrasonic curing. The activation energy of the reaction system in ultrasonic curing was substituted into the modified Kamal autocatalytic equation, and the parameters of the ultrasonic curing kinetic model were estimated by means of an ALO algorithm. Further discussion based on in situ FTIR showed that the non-thermal effect of ultrasonic can affect the vibration strength, stability, and chemical bond energy of internal groups, but cannot cause the fracture of chemical bonds. Moreover, frontier molecular orbital analysis showed that the chemical reactivity of epoxy/amine molecules increased and the HOMO–LUMO energy gap decreased from 6.511 eV to 5.617 eV under the effect of ultrasonic. MDPI 2022-01-27 /pmc/articles/PMC8840220/ /pubmed/35160500 http://dx.doi.org/10.3390/polym14030512 Text en © 2022 by the authors. https://creativecommons.org/licenses/by/4.0/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 (https://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Article Liu, Zhaoyi Wang, Hui Chen, Yizhe Kang, Guodong Hua, Lin Feng, Jindong Study on Curing Kinetics and the Mechanism of Ultrasonic Curing of an Epoxy Adhesive |
title | Study on Curing Kinetics and the Mechanism of Ultrasonic Curing of an Epoxy Adhesive |
title_full | Study on Curing Kinetics and the Mechanism of Ultrasonic Curing of an Epoxy Adhesive |
title_fullStr | Study on Curing Kinetics and the Mechanism of Ultrasonic Curing of an Epoxy Adhesive |
title_full_unstemmed | Study on Curing Kinetics and the Mechanism of Ultrasonic Curing of an Epoxy Adhesive |
title_short | Study on Curing Kinetics and the Mechanism of Ultrasonic Curing of an Epoxy Adhesive |
title_sort | study on curing kinetics and the mechanism of ultrasonic curing of an epoxy adhesive |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8840220/ https://www.ncbi.nlm.nih.gov/pubmed/35160500 http://dx.doi.org/10.3390/polym14030512 |
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