Healable shape memory (thio)urethane thermosets
Urethane-thiourethane networks combining shape memory properties and the
ability to self-heal under mild temperature conditions via Diels-Alder
(DA) chemistry were developed. As a result of the shape recovery effect,
no external force was needed to bring the fracture surfaces into
intimate contact during the healing process. Four network architectures
with DA net-points were evaluated. Two systems were composed of either
bismaleimidic or bisfuranic semi-crystallized polycaprolactone chains
acting as shape memory switching segments (T-trans = T-m), whereas the
other two networks consisted of bis-/trismale-imidic and trisfuranic
monomers and displayed glass transitions for initiating shape recovery
behaviour (T-trans = T-g). The formation of the DA cross-links, the DA
reversibility and shape memory assisted scratch healing of the materials
were studied by FTIR and H-1-NMR spectrometry, differential scanning
calorimetry, optical microscopy and tensile measurements. The results
indicated that the healing efficiency of scratches depends strongly on
the shape recovery ability, without which crack closure and thus the
healing reaction could not occur. Two materials were found to feature
good shape memory properties as well as efficient scratch-healing
capacities, showing mechanical recoveries of 70-80% and the almost
complete disappearance of scratches after healing at a mild temperature
of 60 degrees C for 1-3 days. These materials could find applications in
diverse fields such as self-healing coatings.
Title:
Healable shape memory (thio)urethane thermosets | |
Authors: | Nguyen, T. Le Thu Truong, Thu Thuy Nguyen, Tran Ha |
Keywords: | SELF-HEALING POLYMERS DIELS-ALDER REACTION POLYURETHANES |
Issue Date: | 2015 |
Publisher: | ROYAL SOC CHEMISTRY, THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND |
Citation: | ISIKNOWLEDGE |
Abstract: | Urethane-thiourethane networks combining shape memory properties and the ability to self-heal under mild temperature conditions via Diels-Alder (DA) chemistry were developed. As a result of the shape recovery effect, no external force was needed to bring the fracture surfaces into intimate contact during the healing process. Four network architectures with DA net-points were evaluated. Two systems were composed of either bismaleimidic or bisfuranic semi-crystallized polycaprolactone chains acting as shape memory switching segments (T-trans = T-m), whereas the other two networks consisted of bis-/trismale-imidic and trisfuranic monomers and displayed glass transitions for initiating shape recovery behaviour (T-trans = T-g). The formation of the DA cross-links, the DA reversibility and shape memory assisted scratch healing of the materials were studied by FTIR and H-1-NMR spectrometry, differential scanning calorimetry, optical microscopy and tensile measurements. The results indicated that the healing efficiency of scratches depends strongly on the shape recovery ability, without which crack closure and thus the healing reaction could not occur. Two materials were found to feature good shape memory properties as well as efficient scratch-healing capacities, showing mechanical recoveries of 70-80% and the almost complete disappearance of scratches after healing at a mild temperature of 60 degrees C for 1-3 days. These materials could find applications in diverse fields such as self-healing coatings. |
Description: | POLYMER CHEMISTRY Volume: 6 Issue: 16 Pages: 3143-3154 Published: 2015 ; TNS05812 |
URI: | http://pubs.rsc.org/en/Content/ArticleLanding/2015/PY/C5PY00126A#!divAbstract http://repository.vnu.edu.vn/handle/VNU_123/33070 |
ISSN: | 1759-9954 |
Appears in Collections: | Bài báo của ĐHQGHN trong Web of Science |
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