Upcycling of Carbon Fiber/Thermoset Composites into High‐Performance Elastomers and Repurposed Carbon Fibers

• Published in: Angewandte Chemie International Edition 2024-05, Vol.63 (22), p.e202403972-n/a
• Main Authors: Yang, Tiantian, Lu, Xingyuan, Wang, Xiaohan, Wei, Xiang, An, Ni, Li, Yixuan, Wang, Wenjie, Li, Xiang, Fang, Xu, Sun, Junqi
• Format: Article
• Language: English
• Subjects: Adhesion; Adhesive strength; Bonding strength; Carbon; Carbon fiber reinforced plastics; Carbon Fiber-Reinforced Polymer Composites; Carbon fibers; Chemical Upcycling; Dimethyl acetamide; Elastomers; Materials Science; Polymer matrix composites; Polymers; Polyurethane; Polyurethane resins; Sustainable Chemistry; Tensile strength; Thermosetting resins
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202403972

Recycling of carbon fiber‐reinforced polymer composites (CFRCs) based on thermosetting plastics is difficult. In the present study, high‐performance CFRCs are fabricated through complexation of aromatic pinacol‐cross‐linked polyurethane (PU−AP) thermosets with carbon fiber (CF) cloths. PU−AP thermosets exhibit a breaking strength of 95.5 MPa and toughness of 473.6 MJ m−3 and contain abundant hydrogen‐bonding groups, which can have strong adhesion with CFs. Because of the high interfacial adhesion between CF cloths and PU−AP thermosets and high toughness of PU−AP thermosets, CF/PU−AP composites possess a high tensile strength of >870 MPa. Upon heating in N,N‐dimethylacetamide (DMAc) at 100 °C, the aromatic pinacols in the CF/PU−AP composites can be cleaved, generating non‐destructive CF cloths and linear polymers that can be converted to high‐performance elastomers. The elastomers are mechanically robust, healable, reprocessable, and damage‐resistant with an extremely high tensile strength of 74.2 MPa and fracture energy of 149.6 kJ m−2. As a result, dissociation of CF/PU−AP composites enables the recovery of reusable CF cloths and high‐performance elastomers, thus realizing the upcycling of CF/PU−AP composites. High‐performance carbon fiber‐reinforced polymer composites (CFRCs) are fabricated through complexation of aromatic pinacol‐crosslinked polyurethane thermosets with CF cloths. Upon heating CFRCs in N,N‐dimethylacetamide, polyurethane thermosets are cleaved into linear polymers, which generates non‐destructive CF cloths and value‐added healable and reprocessable elastomers with high mechanical strength and damage resistance.