Repeatable Photoinduced Self‐Healing of Covalently Cross‐Linked Polymers through Reshuffling of Trithiocarbonate Units

Abstract

Gut geheilt: Mit Trithiocarbonat(TTC)‐Einheiten vernetzte Polymere wurden durch RAFT‐Polymerisation hergestellt. Die selbstheilenden Systeme oder makroskopischen Zusammenschlüsse entstanden bei UV‐Bestrahlung des vernetzten Polymers in Lösung und im Festkörper. Es gelang sogar der Zusammenschluss vollständig getrennter Teile (siehe Bilder, BA=n‐Butylacrylat).

Room temperature self-healable epoxy elastomer with reversible alkoxyamines as crosslinkages

“…To confirm that the self-healing behavior is only due to the disconnection/reconnection of C-ON bonds, reference tests were performed on the specimens of HDODGE and PEGDGE, which do not contain any alkoxyamines but carry similar epoxy end groups cured by the same hardener. It was found that no healing effect can be detected under the same conditions, indicating that the entanglement of dangling chains across the fractured surfaces is negligible so that it M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT 15 does not make any contribution to the restoration of the material strength.…”

“…So far, the healing chemistries involved can be classified into non-covalent [6][7][8][9][10][11] and dynamic covalent interactions [12][13][14][15][16][17][18][19][20][21][22][23][24][25]. The former includes hydrogen bonding [6], π-π stacking [7], ionic interaction [8], host-guest interaction [9], metal-ligand coordination [10], and supramolecular interaction [11], while the latter deals with Diels-Alder (DA) reaction [12], acylhydrazone bonds [13], boronic ester linkages [14], trithiocarbonate [15], thiuram disulfide units [16], disulfide-thiol exchange reactions [17], disulfide metathesis [18], coumarin derivatives [19], alkoxyamine moieties [20], siloxane equilibration [21], transesterification [22], diarylbibenzofuranone links [23], Ru-catalyzed shuffling of C=C double bonds [24], and urea bonds [25].…”

Self-healing Hydrogels Based on Dynamic Chemistry and Their Biomedical Applications

“…例如, 基于可逆二硫键的多 臂高分子 [38] 、光引发修复的三硫代碳酸酯交联网络结 构 [39] 、紫外光修复的壳聚糖-聚氨酯复合材料 [40,41] 、热 引发修复的 Diels-Alder 化学交联结构及基于自由基交 换引发愈合的凝胶材料 [42,43] . 虽然一部分文献中的条件变化是 温和的 [48,49] , …”

Reconfigurable surface patterns on covalent adaptive network polymers using nanoimprint lithography

“…This smart material behavior has generated substantial interest in utilizing the photoplasticity [1,2], stress relaxation [3], and self-healing [4] capabilities of similar materials [5e10]. These materials, known as covalent adaptive networks (CANs) differ from the permanent and static networks associated with traditional thermosets in that their internal covalent bonds can be broken and reformed.…”