High-Temperature Steam Degradation Behavior of Carbon Fiber/Epoxy Composites with Different Structures

Abstract Addressing the challenges of difficult disposal and low resource utilization of carbon fiber reinforced epoxy resin composite waste, this study systematically investigated the behavioral differences of carbon fiber composites with different molding processes and structural configurations during high-temperature steam degradation. A comparative study was conducted on the degradation characteristics of two typical epoxy resin systems cured with dicyandiamide and anhydride, respectively. The influence of material structural features on steam mass transfer and resin degradation was revealed, and the mechanism by which resin chemical structure affects hydrolytic degradation behavior was elucidated. The results demonstrated that the primary degradation temperature range for dicyandiamide-cured epoxy resin was 350-420 ℃, while the degradation temperature range for anhydride-cured epoxy resin shifted toward higher temperatures. Considering both resin removal efficiency and mechanical property retention, 500 ℃ was identified as the optimal processing temperature, at which the tensile strength retention rate of recycled carbon fibers reached 93.5%. The high-temperature steam degradation technology exhibited excellent applicability to carbon fiber composites with various structures, providing valuable reference for green and high-value recycling of waste carbon fiber composite materials.