Review of conventional and emerging recycling methods for carbon fiber-reinforced thermoset polymer composites: challenges and future perspectives.

Carbon fiber-reinforced polymer (CFRP) composites play critical roles in advanced industries due to their high strength-to-weight ratio and durability; however, CFRP waste management and recycling have become an environmental and economic necessity. Landfilling these composites, after their service life, wastes valuable resources of reinforcing fibers (such as carbon fibers) and may release toxic byproducts. Despite significant advances in this field, recycling CFRP composites remains a challenge. Thus, it is crucial to develop efficient, clean, and cost-effective methods for recycling CFRP, especially to preserve the value of both the fibers and thermoset polymer matrix components. This review study covers current CFRP recycling technologies, including the chemical, thermal, and mechanical recovery of CFRP composites across various matrix types (such as epoxy and phenolic, and other thermoset matrices). Also, recent developments have introduced advanced techniques such as carbonization, solvothermal, electrochemical, sonochemical, and biological recycling. These methods aim to improve fiber recovery while reducing energy consumption and preserving material quality. Future advancements are expected to focus on hybrid and multifunctional recycling systems integrated within circular economy frameworks, enabling closed-loop processes and reducing reliance on virgin resources. Such innovations will transform CFRP composites from waste into valuable sustainable resources.