Research progress in dynamic covalent thermosets and their composites based on dynamic covalent bonds

Fiber reinforced thermosetting composites exhibit high strength-weight ratio， high modulus-weight ratio， and good thermostability， and have been applied in many high-tech areas such as aerospace. However， these materials face extreme difficulty in reprocessing and recycling after the molding process. To solve the above problem， the dynamic covalent bonds are introduced into resin networks to design the dynamic covalent thermosets， exhibiting recyclability and remolding dynamic properties similar to thermoplastic polymers， providing an effective method. In this review， the development， characteristic， and network regulation strategies of thermosets with dynamic covalent bonds were introduced. The characteristics of fiber reinforced composites derived from these thermosets were summarized. Based on the classification of dynamic covalent bond type， the research progress of transesterification reactions， disulfide metathesis， imine metathesis， and other bond exchange thermosetting resins and fiber reinforced composites was reviewed. The development tendency and commercial applications of these composites were briefly overviewed. Finally， the future development direction and design suggestions of these thermosets and composites are concluded， providing ideas for the preparation and commercial application of these materials.