Facile preparation, closed-loop recycling of multifunctional carbon fiber reinforced polymer composites

Recyclable carbon fiber reinforced polymer (CFRP) composites have attracted considerable attention in recent years due to the combined merits of excellent mechanical and thermal properties, recyclability and reprocess -ability. This paper reports on the successful preparation of closed-loop recyclable CFRP by in-situ polymerization and dynamic cross-linking (ISPDC) technology. The SEM, XPS and monofilament tensile curves were measured to investigate the morphology, chemical details, and mechanical properties of the recycled carbon fiber (CF); the chemical structure of the degraded resin was further characterized and analyzed according to the NMR and FTIR spectra. The obtained results show that under mild acidic conditions, the CFRP was degraded to high-quality recycled CF and linear polymer with methacrylic acid units, which can be used to prepare regenerated CFRP. In addition, due to the dynamic feature of the hemiacetal ester structure in the CFRP matrix, the CFRP also exhibited multiple functions, such as rapid welding, reprocessing, shape shifting, and self-healing, as well as the extremely long shelf life of composite prepregs. Our analysis of the recycling and dynamic exchange processes indicates that the strategy of embedding a releasable linker is dominant for the preparation of closed-loop recyclable and multifunctional CFRP.

Automated summary

This study successfully prepared a closed-loop recyclable carbon fiber reinforced polymer (CFRP) composite through in-situ polymerization and dynamic cross-linking technology. The degraded CFRP can be transformed into high-quality recycled carbon fiber and linear polymer under mild acidic conditions. The CFRP also demonstrated multiple functions such as rapid welding, reprocessing, shape shifting, and self-healing due to the dynamic feature of the matrix. The strategy of embedding a releasable linker is crucial for the preparation of closed-loop recyclable and multifunctional CFRP.