Catalyst-free self-healing bio-based vitrimer for a recyclable, reprocessable, and self-adhered carbon fiber reinforced composite

Carbon fiber reinforced composites (CFRPs) have the problems of over-reliance on petroleum-based products and difficult recycling of Carbon fibers (CFs). To solve these problems, a degradable Epoxidized menthane diamine–adipic acid (EMDA–AA) vitrimer matrix for CFRPs is obtained from bio-based menthane diamine and adipic acid. Owing to the rigid six-membered ring structure of EMDA, the EMDA–AA vitrimer matrix exhibits good mechanical properties. With the autocatalysis of tertiary amines in the EMDA–AA vitrimer, the vitrimer network can achieve topological rearrangement via dynamic transesterification reactions without additional catalysts. The fabricated vitrimer exhibits excellent self-healing, shape memory and reprocessing properties. Moreover, EMDA–AA–CF composite with EMDA–AA epoxy vitrimer as the matrix resin shows excellent reprocessing, shape memory and self-adhesive properties. In addition, the EMDA–AA vitrimer matrix resin can be rapidly degraded into polyols by amination reaction with ethanolamine under mild conditions, resulting in the efficient recycling of Carbon fibers (CFs). Scanning electron microscopy, Raman spectroscopy, and tensile tests show that the recycled CFs have almost the same chemical structure and mechanical properties as the virgin CFs. This study can assist in the preparation of green and high-strength CFRPs using recyclable bio-based epoxy vitrimer matrices and provide a strategy for efficient recycling of CFs from CFRPs.