Recycling of Carbon Fiber Reinforced Epoxy Resin Composites Based on Microwave Assisted Swelling Method

Abstract

Due to the lack of efficient and stable recycling methods and processes, the waste of carbon fiber-reinforced polymer (CFRP) poses a threat to the environment, while a large number of demand every year requires a lot of cost and energy to be used in manufacturing carbon fiber (CF). Therefore, there is an urgent need to develop an economical and efficient recycling process to deal with waste CFRP. In this study, CFRP in N-methylpyrrolidone (NMP) solution was swelled with the assistance of microwave irradiation. And the high efficiency and fast characteristics of microwave irradiation promoted the swelling of CFRP in NMP, which greatly reduced the pretreatment temperature and time. The CFRP was successfully swollen at 80 °C for only 0.5 h, then, they were decomposed in 8 M nitric acid for 7 h, the decomposition rate reached 74.6%, which greatly improved the reaction rate and finally retained about 70% of the CF mechanical properties. This method is helpful to reduce energy consumption in the recovery process and improve the stability of recycled CF (rCF), which provides a new direction and theoretical support for the recovery and reuse of CF.