Healable,Recyclable, and Mechanically Tough Polyurethane Elastomers with Exceptional Damage Tolerance |
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Authors: | Xiaohan Wang Shengnan Zhan Zhongyuan Lu Jian Li Xiao Yang Yongna Qiao Yongfeng Men Junqi Sun |
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Affiliation: | 1. State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Qianjin Street 2699, Changchun, 130012 P. R. China;2. State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Renmin Street 5625, Changchun, 130022 P. R. China |
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Abstract: | There is a huge requirement of elastomers for use in tires, seals, and shock absorbers every year worldwide. In view of a sustainable society, the next generation of elastomers is expected to combine outstanding healing, recycling, and damage-tolerant capacities with high strength, elasticity, and toughness. However, it remains challenging to fabricate such elastomers because the mechanisms for the properties mentioned above are mutually exclusive. Herein, the fabrication of healable, recyclable, and mechanically tough polyurethane (PU) elastomers with outstanding damage tolerance by coordination of multiblock polymers of poly(dimethylsiloxane) (PDMS)/polycaprolactone (PCL) containing hydrogen and coordination bonding motifs with Zn2+ ions is reported. The organization of bipyridine groups coordinated with Zn2+ ions, carbamate groups cross-linked with hydrogen bonds, and crystallized PCL segments generates phase-separated dynamic hierarchical domains. Serving as rigid nanofillers capable of deformation and disintegration under an external force, the dynamic hierarchical domains can strengthen the elastomers and significantly enhance their toughness and fracture energy. As a result, the elastomers exhibit a tensile strength of ≈52.4 MPa, a toughness of ≈363.8 MJ m−3, and an exceptional fracture energy of ≈192.9 kJ m−2. Furthermore, the elastomers can be conveniently healed and recycled to regain their original mechanical properties and integrity under heating. |
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Keywords: | damage tolerance healable materials polyurethane elastomers recyclable materials supramolecular chemistry |
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