Efficient recycling of carbon fiber from carbon fiber reinforced composite and reuse as high performance electromagnetic shielding materials with superior mechanical strength

Carbon fiber reinforced boron phenolic resin composite (CF/BPR) is widely used. However, it is hard to decompose its waste for highly cross-linked networks. Herein, a solvothermal decomposition route was proposed to decompose CF/BPR and recycle carbon fibers. Decomposition ratio of resin (Dr) reached 99.78%. Possible decomposition mechanism was proposed based on characterizations of decomposition products. Composite was decomposed for synergistic effects of physical swelling, mechanical impact and chemical decomposition. Surface morphology and microstructure characterization of recycled carbon fibers (RCFs) confirmed that resin was highly removed while no significant harm was caused to RCFs. It was found that RCFs reinforced boron phenolic resin composite (RCFs/BPR) had superior punch type shear strength due to improved wettability and interfaces. Moreover, RCFs/BPR exhibited superior electromagnetic shielding performance in X-band frequency for improved conductive network. This work presents a facile and efficient pathway for decomposing composite waste and reuse as high performance electromagnetic shielding materials.