Recovery and Characterization of Reinforcing Fibers from Fiber Reinforced Plastics by Thermal Activation of Oxide Semiconductors

A novel system for the recovery of reinforcing fibers from fiber reinforced plastics (FRP) and their recycling technology has been developed on the basis of the thermal activation of semiconductors (TASC). TASC is our new technology characterized by the use of oxidative properties of defect electrons (i.e., hole) of semiconductors. The present technology enables us to totally decompose a polymer matrix in FRP into H2O and CO2 in 10-20 min at about 400-500 degrees C in air, yielding only embedded reinforcing fibers in their original form. Characterization of the recovered glass fibers or carbon fibers has also been carried out by optical microscope, scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), X ray diffraction (XRD), as well as thermogravimetric analysis and differential thermal analysis (TGA/DTA). The analysis revealed that no noticeable difference is recognized between the virgin reinforcing fibers and the recovered ones, but the sizing agent has also totally been removed. Therefore, it is necessary to coat a sizing material again when the recovered fibers are reused for recycling.