Vitrimers with covalent adaptable networks usually show low mechanical properties and water resistivity. Here, we report an epoxy vitrimer which possesses not only high weldability, malleability and programmability, but also outstanding mechanical properties and water insensitivity. Such epoxy vitrimer is fabricated by crosslinking diglycidyl ether of bisphenol F (DGEBF) with a novel curing agent bearing imine backbones and amino terminals. The curing agent is synthesized by a one-pot reaction between 3-aminobenzylamine and terephthalaldehyde by taking advantage of the different reactivity of the aromatic amine and aliphatic amine. The dynamic imine bonds of the curing agent enable malleability, shape reconfiguration and programming of the epoxy vitrimer, while the aromatic structure of the curing agent imparts the epoxy vitrimer with high tensile strength, Young modulus and thermal stability. Moreover, the epoxy vitrimer is highly water-resistant due to the hydrophobicity and high crosslinking density of the network. Such a combination of comprehensive properties and convenient fabrication approach makes the epoxy vitrimer hold great promise to serve as structural materials in diverse applications.
Jiayi Zhou,Wenwei Huang,Yan Zhang,Ming Zhang,Yining Sun,Fangjie Li,Dongye Yang
The rapid advancement of smart actuators has highlighted the challenge of preparing mechanically robust, large-scale films for their fabrication. In this study, xanthan gum, renowned for its excellent water absorption properties, was combined with MXene to create a nacre-inspired composite film reinforced by abundant hydrogen bonds. This unique structure significantly enhances the film's mechanical properties, improving tensile strength and toughness, enabling it to withstand crumpling and folding without damage. MXG exhibited excellent weldability, facilitating the production of large-scale films. The incorporation of micro-wrinkles endows the film with anisotropic mechanical behavior, while its strong water absorption capacity enables programmable humidity-driven actuation under a gradient. The actuator demonstrates rapid response speeds, substantial bending curvatures, and excellent cyclic stability. Furthermore, leveraging the photothermal properties of MXene, the film generates a photothermal Marangoni effect under light irradiation, enabling programmable and directional movement on water surfaces. With superior mechanical performance, weldability, and photothermal responsiveness, this composite film shows great potential for manufacturing large-scale actuators with applications in cargo transportation, intelligent robotics, and soft devices.
危险品化学品经营许可证（带存储）