Xiaoyu Huang,Chen Ding,Yichun Wang,Songmao Zhang,Xiuhui Duan,Hongzeng Ji
Novel reprocessable thermosetting adhesives (RTAs), which combine high adhesive strength, reusability, disassembly, and recyclability features, have attracted increasing attention. However, developing RTAs with a rapidly adhesive rate while ensuring high adhesive strength and self-healing ability is still a significant challenge. Here, we prepared a novel vitrimer called DAx–DTSAy, which can be used as an RTA. First, by adjusting the ratio of rigid and flexible segments, maximum tensile strength reached 35.92 MPa. Second, the combined effect of dynamic hydroxyl ester bonds and dynamic disulfide bonds resulted in a rapid stress relaxation behavior, with a complete relaxation time 13.6 times shorter than a vitrimer only cross-linked with hydroxy ester bonds. This feature endowed its good self-healing and reprocessing capabilities. After self-healing at 180 °C, the maximum healing rate of mechanical properties was 91.8%. After three reprocesses, the maximum recovery rate of tensile strength was 120.2%. Furthermore, the combination of rigid and flexible segments and the synergistic effect of dual dynamic covalent bonds made DAx–DTSAy capable of use as a high-performance RTA. The lap shear strength of a DAx–DTSAy film on stainless steel reached 18.18 MPa after 15 min, with a recovery rate of 91.9% after 5 rebonding cycles. Additionally, DAx–DTSAy can be disassembled in chemical agents and exhibited better insulation properties compared to traditional epoxy resins. DAx–DTSAy can be employed as a novel high-performance adhesive in applications such as electronic devices and transportation, contributing to the development of thermosetting adhesives toward recyclability and sustainability.
The development of nano-reinforced materials to form structural composites relies on controlling interfaces between nanomaterials and the bulk material to yield materials that can be applied in fields such as aerospace, wind power energy, and transportation. This paper describes experiments to design and control micro–nano multi-scale interfacial reinforced composites of carbon fiber using electrodeposition and electropolymerization in a one-step method. First, the adhesion of graphene oxide (GO) nanosheets on the fiber surface was effectively enhanced through the simultaneous deposition of GO nanosheets and electro-grafting of monomers. The deposition efficiency of GO nanosheets was significantly boosted with polymerization of monomers. The interlaminar shear strength and interfacial shear strength of the composites treated for only 120 s were increased from 40.8 and 50.5 to 54.6 and 73.9 MPa, an increase of 33.8 and 46.3%, respectively. Investigation of the mechanism of failure of the composites showed that it was due to the cohesive failure of the resin from interfacial debonding. This paper reports a theoretical and experimental basis for the continuous preparation of nano-reinforced carbon fiber and high-performance advanced composites.
危险品化学品经营许可证（带存储）