The impact of thermal treatment parameters on the preservation of carbon fiber mechanical properties after reclamation

Carbon fiber, despite its exceptional properties, remains underutilized due to monetary and environmental concerns. Concurrently, the imminent challenge associated with rising quantities of End-of-Life CFRP (carbon fiber reinforced polymer) demands the further development of recycling strategies. This study focuses on optimizing the recycling process parameters of pyrolysis and oxidation thermal treatment to maximize the retention of mechanical properties in the recycled fibers in the shortest process time. To assess the result of the pyrolysis, single fiber tensile tests were executed to measure strength and stiffness. Additionally, microscopy and spectroscopy studies were carried out to evaluate fiber geometry as well as surface quality. At the laboratory scale, experiments demonstrated that the combination of pyrolysis and oxidation yields clean, reusable fibers with mechanical properties suitable for secondary applications. The influence of various treatment parameters on the strength and stiffness of the recycled fibers was explored, establishing a clear correlation. The outcome is a set of optimized parameters that contribute to mechanical property retention, including a novel recycling method that allows for reduced processing times, as short as 10 min. This work paves the way for a more eco-friendly and cost-effective approach to harnessing the potential of carbon fiber in a wide range of applications while mitigating environmental concerns associated with landfill disposal.