Intrinsically self-healing crosslinked elastomer with mechanically robust based on dynamic urea bond and hydrogen bond for smart humidity sensor

作者：Lu, Liwei; Sun, Xia; Guo, Aohuan; Yu, Hancheng; Yu, Caili; Zhou, Zhongqun^*; Zhang, Faai^*

来源：REACTIVE & FUNCTIONAL POLYMERS, 2023, 192: 105737.

DOI：10.1016/j.reactfunctpolym.2023.105737

• Self-healing
• Crosslinked elastomer
• Dynamic urea bond
• Hydrogen bond
• Humidity sensor

Employment of noncovalent bonds as reversible crosslinks have been applied in weldable and self-healing crosslinked polymer networks but result in limited mechanical properties. Herein, a robust, tunable, and fast healable poly(urethane-urea)-GMA (PG) elastomer with a combination of multiple hydrogen bonds and dynamic covalent urea bonds was designed via a photo-induced copolymerization. The resultant PG60 exhibited a tensile strength of 12.3 MPa, an elongation at break of 229%, a toughness of 16.08 MJ m  3, and a self-healing efficiency of 100.0%. By adjusting the content of dynamic crosslinkers, the mechanical strength and self-healability of the resulting elastomers can be optimized. The exceptional properties of the networks, including self-healing capability and remarkable robust mechanical behavior, are attributed to the presence of reversibly non-covalent hydrogen bonds and dynamically covalent urea bonds, which have been confirmed through stress relaxation tests. More importantly, this study not only presents a facile fabrication method for designing me-chanically robust and fast self-healing crosslinked elastomers, but also shows great potential in smart humidity sensor.

• 单位
  茂名学院; 桂林理工大学