TY - JOUR
T1 - Mechanophores with a reversible radical system and freezing-induced mechanochemistry in polymer solutions and gels
AU - Imato, Keiichi
AU - Irie, Atsushi
AU - Kosuge, Takahiro
AU - Ohishi, Tomoyuki
AU - Nishihara, Masamichi
AU - Takahara, Atsushi
AU - Otsuka, Hideyuki
PY - 2015/5/18
Y1 - 2015/5/18
N2 - Visualization and quantitative evaluation of covalent bond scission in polymeric materials are highly important for understanding failure, fatigue, and deterioration mechanisms and improving the lifetime, durability, toughness, and reliability of the materials. The diarylbibenzofuranone-based mechanophore radical system enabled, through electron paramagnetic resonance spectroscopy, in situ quantitative evaluation of scission of the mechanophores and estimation of mechanical energy induced along polymer chains by external forces. The coagulation of polymer solutions by freezing probably generated force but did not cleave the mechanophores. On the other hand, cross-linking led to efficient propagation of the force of more than 80 kJ?mol-1 to some mechanophores, resulting their cleavage and generation of colored stable radicals. This mechanoprobe concept has the potential to elucidate other debated issues in the polymer field as well.
AB - Visualization and quantitative evaluation of covalent bond scission in polymeric materials are highly important for understanding failure, fatigue, and deterioration mechanisms and improving the lifetime, durability, toughness, and reliability of the materials. The diarylbibenzofuranone-based mechanophore radical system enabled, through electron paramagnetic resonance spectroscopy, in situ quantitative evaluation of scission of the mechanophores and estimation of mechanical energy induced along polymer chains by external forces. The coagulation of polymer solutions by freezing probably generated force but did not cleave the mechanophores. On the other hand, cross-linking led to efficient propagation of the force of more than 80 kJ?mol-1 to some mechanophores, resulting their cleavage and generation of colored stable radicals. This mechanoprobe concept has the potential to elucidate other debated issues in the polymer field as well.
KW - cross-linked polymers
KW - dynamic covalent chemistry
KW - gels
KW - mechanochemistry
KW - mechanochromism
UR - http://www.scopus.com/inward/record.url?scp=84929105206&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84929105206&partnerID=8YFLogxK
U2 - 10.1002/anie.201412413
DO - 10.1002/anie.201412413
M3 - Article
AN - SCOPUS:84929105206
SN - 1433-7851
VL - 54
SP - 6168
EP - 6172
JO - Angewandte Chemie - International Edition
JF - Angewandte Chemie - International Edition
IS - 21
ER -