Energy-efficient chemical recycling of CFRP and analysis of the interfacial shear strength on recovered carbon fiber.

ABSTRACT

Here we report a novel chemical recycling of carbon fiber-reinforced plastic (CFRP) using meta-chloroperoxybenzoic acid (mCPBA) as the representative oxidizing agent. The optimal decomposition conditions for the epoxy (EP) resin in CFRP were investigated by varying mCPBA concentration and reaction time. The CFRP decomposed completely within 6 h using a 1.5 M mCPBA solution at 40 °C. Tensile strength of recovered CF (r-CF) measured 4.4 GPa, 93.6% of virgin CF (v-CF), and electrical conductivity reached 590 S/cm, 95% of v-CF. Furthermore, the interfacial shear strength (IFSS) of the recovered carbon fibers (r-CF) using EP resin and polyamide 6 (PA6) was analyzed. For EP resin, the IFSS of r-CF was 88 MPa, a 26 % increase compared to v-CF. In the case of PA6 resin, IFSS values were 80 MPa for r-CF, a 17% improvement over v-CF. The study highlights superior mechanical properties and favorable IFSS of r-CF, positioning them as promising for composite regeneration. Remarkably, this method operated at relatively low temperatures compared to existing technologies, with energy consumption recorded at 35 MJ/kg, establishing it as the most energy-efficient recycling method available.