Cover Image

Microencapsulated healing agents for an elevated-temperature cured epoxy: influence of viscosity on healing efficiency

Among many applications, elevated-temperature cured epoxy resins are widely used for high-performance applications especially for structural adhesive and as a matrix for structural composites. This is due to their superior chemical and mechanical properties. The thermosetting nature of epoxy produce...

Full description

Saved in:
Bibliographic Details
Main Authors: Ghazali, Habibah, Ye, Lin, Amir, Amie N.
Format: Article
Language:English
Published: SAGE Publications Ltd 2021
Subjects:
TJ Mechanical engineering and machinery
Online Access:http://eprints.utm.my/id/eprint/95708/1/HabibahGhazali2021_MicroencapsulatedHealingAgentsforanElevated.pdf
http://eprints.utm.my/id/eprint/95708/
http://dx.doi.org/10.1177/09673911211045373
Tags: Add Tag
No Tags, Be the first to tag this record!
id my.utm.95708
record_format eprints
spelling my.utm.957082022-05-31T13:18:00Z http://eprints.utm.my/id/eprint/95708/ Microencapsulated healing agents for an elevated-temperature cured epoxy: influence of viscosity on healing efficiency Ghazali, Habibah Ye, Lin Amir, Amie N. TJ Mechanical engineering and machinery Among many applications, elevated-temperature cured epoxy resins are widely used for high-performance applications especially for structural adhesive and as a matrix for structural composites. This is due to their superior chemical and mechanical properties. The thermosetting nature of epoxy produces a highly cross-linked polymer network during the curing process where the resulting material exhibited excellent properties. However, due to this cross-linked molecular structure, epoxies are also known to be brittle, and once a crack initiated in the material, it is difficult to arrest the crack propagation. Earlier research found that the inclusion of encapsulated healing agents is able to introduce self-healing ability to the room-temperature cured epoxies. The current study investigated the self-healing behaviour of an elevated-temperature cured epoxy, which incorporated the dual-capsule system loaded with diglycidyl-ether of bisphenol-A (DGEBA) resin and mercaptan. The microcapsules were prepared by the in-situ polymerisation method while the fracture toughness and the self-healing capability of the tapered-double-cantilever-beam (TDCB) epoxy specimens were measured under Mode-I fracture toughness testing. We investigated the effect of temperature on viscosity of the healing agents and how these values influence the formation of uniform healing on the fracture surfaces. It was found that incorporation of the dual-capsule self-healing system onto an elevated-temperature cured epoxy slightly changed the fracture toughness of the epoxy as indicated by the Mode-I testing. In the case of thermal healing at 70°C, the self-healing epoxy exhibited a recovery of up to 111% of its original fracture toughness, where a uniform spreading of the healant was observed. The excellent healing behaviour is attributed to the lower viscosity of the healant at higher temperature and the higher glass transition temperature (Tg) of the produced healant film. The DSC analysis confirmed that the healing process was not contributed by the post-curing of the host epoxy. SAGE Publications Ltd 2021-11 Article PeerReviewed application/pdf en http://eprints.utm.my/id/eprint/95708/1/HabibahGhazali2021_MicroencapsulatedHealingAgentsforanElevated.pdf Ghazali, Habibah and Ye, Lin and Amir, Amie N. (2021) Microencapsulated healing agents for an elevated-temperature cured epoxy: influence of viscosity on healing efficiency. Polymers and Polymer Composites, 29 (9). S1317-S1327. ISSN 0967-3911 http://dx.doi.org/10.1177/09673911211045373 DOI:10.1177/09673911211045373
institution Universiti Teknologi Malaysia
building UTM Library
collection Institutional Repository
continent Asia
country Malaysia
content_provider Universiti Teknologi Malaysia
content_source UTM Institutional Repository
url_provider http://eprints.utm.my/
language English
topic TJ Mechanical engineering and machinery
spellingShingle TJ Mechanical engineering and machinery
Ghazali, Habibah
Ye, Lin
Amir, Amie N.
Microencapsulated healing agents for an elevated-temperature cured epoxy: influence of viscosity on healing efficiency
description Among many applications, elevated-temperature cured epoxy resins are widely used for high-performance applications especially for structural adhesive and as a matrix for structural composites. This is due to their superior chemical and mechanical properties. The thermosetting nature of epoxy produces a highly cross-linked polymer network during the curing process where the resulting material exhibited excellent properties. However, due to this cross-linked molecular structure, epoxies are also known to be brittle, and once a crack initiated in the material, it is difficult to arrest the crack propagation. Earlier research found that the inclusion of encapsulated healing agents is able to introduce self-healing ability to the room-temperature cured epoxies. The current study investigated the self-healing behaviour of an elevated-temperature cured epoxy, which incorporated the dual-capsule system loaded with diglycidyl-ether of bisphenol-A (DGEBA) resin and mercaptan. The microcapsules were prepared by the in-situ polymerisation method while the fracture toughness and the self-healing capability of the tapered-double-cantilever-beam (TDCB) epoxy specimens were measured under Mode-I fracture toughness testing. We investigated the effect of temperature on viscosity of the healing agents and how these values influence the formation of uniform healing on the fracture surfaces. It was found that incorporation of the dual-capsule self-healing system onto an elevated-temperature cured epoxy slightly changed the fracture toughness of the epoxy as indicated by the Mode-I testing. In the case of thermal healing at 70°C, the self-healing epoxy exhibited a recovery of up to 111% of its original fracture toughness, where a uniform spreading of the healant was observed. The excellent healing behaviour is attributed to the lower viscosity of the healant at higher temperature and the higher glass transition temperature (Tg) of the produced healant film. The DSC analysis confirmed that the healing process was not contributed by the post-curing of the host epoxy.
format Article
author Ghazali, Habibah
Ye, Lin
Amir, Amie N.
author_facet Ghazali, Habibah
Ye, Lin
Amir, Amie N.
author_sort Ghazali, Habibah
title Microencapsulated healing agents for an elevated-temperature cured epoxy: influence of viscosity on healing efficiency
title_short Microencapsulated healing agents for an elevated-temperature cured epoxy: influence of viscosity on healing efficiency
title_full Microencapsulated healing agents for an elevated-temperature cured epoxy: influence of viscosity on healing efficiency
title_fullStr Microencapsulated healing agents for an elevated-temperature cured epoxy: influence of viscosity on healing efficiency
title_full_unstemmed Microencapsulated healing agents for an elevated-temperature cured epoxy: influence of viscosity on healing efficiency
title_sort microencapsulated healing agents for an elevated-temperature cured epoxy: influence of viscosity on healing efficiency
publisher SAGE Publications Ltd
publishDate 2021
url http://eprints.utm.my/id/eprint/95708/1/HabibahGhazali2021_MicroencapsulatedHealingAgentsforanElevated.pdf
http://eprints.utm.my/id/eprint/95708/
http://dx.doi.org/10.1177/09673911211045373
_version_ 1735386837451538432
score 13.211869

Similar Items