Premium
Mechanophores with a Reversible Radical System and Freezing‐Induced Mechanochemistry in Polymer Solutions and Gels
Author(s) -
Imato Keiichi,
Irie Atsushi,
Kosuge Takahiro,
Ohishi Tomoyuki,
Nishihara Masamichi,
Takahara Atsushi,
Otsuka Hideyuki
Publication year - 2015
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201412413
Subject(s) - mechanochemistry , polymer , covalent bond , bond cleavage , electron paramagnetic resonance , radical , materials science , durability , cleave , chain scission , chemistry , nanotechnology , photochemistry , chemical engineering , organic chemistry , composite material , physics , nuclear magnetic resonance , engineering , enzyme , catalysis
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.