Ultraviolet (UV)-curing technology as a photopolymerization technology has received widespread attention due to its advantages of high efficiency, wide adaptability, and environmental friendliness. Ultraviolet-based 3D printing technology has been widely used in the printing of thermosetting materials, but the permanent covalent cross-linked networks of thermosetting materials which are used in this method make it hard to recover the damage caused by the printing process through reprocessing, which reduces the service life of the material. Therefore, introducing dynamic bonds into UV-curable polymer materials might be a brilliant choice which can enable the material to conduct self-healing, and thus meet the needs of practical applications. The present review first introduces photosensitive resins utilizing dynamic bonds, followed by a summary of various types of dynamic bonds approaches. We also analyze the advantages/disadvantages of diverse UV-curable self-healing polymers with different polymeric structures, and outline future development trends in this field.

In this work, the PEEK/short carbon fiber (CF) composites were prepared, a new thermodynamic coupling (preheating and impact compaction) process of the FDM method is proposed, and the warp deformation mechanism was obtained by finite element simulation analysis. Results show that a new method could improve the forming quality of an FDM sample. The porosity of FDM samples of the PEEK/CF composite gradually decreased from 10.15% to 6.83% with the increase in impact temperature and frequency. However, the interlayer bonding performance was reduced from 16.9 MPa to 8.50 MPa, which was attributed to the influence of the printing layer height change from the printhead to the forming layer. To explain the above phenomenon, a thermodynamic coupling model was established and a relevant mechanism was analyzed to better understand the interlayer mechanical and porosity properties of PEEK/CF composites. The study reported here provides a reference for improving the forming quality of fabricated PEEK/CF composites by FDM.

Mechanical properties and reprocessing properties are of great significance to the serviceability and recyclability of energetic composites. However, the mechanical robustness of mechanical properties and dynamic adaptability related to reprocessing properties are inherent contradictions, which are difficult to optimize at the same time. This paper proposed a novel molecular strategy. Multiple hydrogen bonds derived from acyl semicarbazides could construct dense hydrogen bonding arrays, strengthening physical cross-linking networks. The zigzag structure was used to break the regular arrangement formed by the tight hydrogen bonding arrays, so as to improve the dynamic adaptability of the polymer networks. The disulfide exchange reaction further excited the polymer chains to form a new “topological entanglement”, thus improving the reprocessing performance. The designed binder (D2000-ADH-SS) and nano-Al were prepared as energetic composites. Compared with the commercial binder, D2000-ADH-SS simultaneously optimized the strength and toughness of energetic composites. Due to the excellent dynamic adaptability of the binder, the tensile strength and toughness of the energetic composites still maintained the initial values, 96.69% and 92.89%, respectively, even after three hot-pressing cycles. The proposed design strategy provides ideas for the design and preparation of recyclable composites and is expected to promote the future application in energetic composites.