热固性树脂基复合材料的变革性制造方法研究进展

The permanently covalent cross-links in thermosetting polymers is a worldwide concern that impedes degradation and recycling as well as joining, repairing and 3D-printing of thermoset composites, which remains an enormous challenge in both academic and industrial fields. Great efforts have been devoted to this field, which, however, are not effective and are still open problems. With this regard, the recently-developed covalent adaptable networks (CANs) open up a new window for reprocessing thermoset composites. In view of the typical CANs, we established a multi-scale mechanical model and the correspondingly computational method for surface welding in covalent adaptable networks with assistance of thermal compression. Moreover, we investigated a novel transesterification reaction mechanism assisted with a small hydroxyl-based molecule, and it has been successfully used in the field of pressure-free joining of CANs attaining a maximum interfacial fracture energy of up to 4000 J/m². Simultaneously, a sustainable 3D-printing of CANs was achieved. Also, the surface damage repair of CANs-based thermosetting composites as well as near 100% reclamation and re-fabrication for CANs resins and fabrics have been attained. Particularly, this has been extended to the successful recycling of advanced carbon- and glass-fabrics from industrial grade epoxy composites. These tries possess a tremendous potential to be the revolutionary fabrication method for thermoset composites. Accordingly, this article systematically reviews the advances in CANs mentioned above and highlights their current issues and challenges. Finally, we suggest an outlook on the future of theoretical model, material design and industrial application of CANs that are in highly demanded.