Characterization of Carbon Fibers Recovered by Pyrolysis of Cured Prepregs and Their Reuse in New Composites

Abstract

The applications of composite materials are rapidly growing. In the aeronautical sector, composites account for up to 50% of the weight of a modern typical commercial aircraft. However, the amount of composites currently recycled is less than 5% of the total amount produced. With environmental concerns becoming an increasingly influential topic, recy clability of composite materials is a key issue. Furthermore, several related European laws have been passed to minimize the environmental impact of composite structures and to make rational use of landfills. In this chapter, the authors analyze recycling tech - niques for carbon fiber composites with thermoset polymer matrix. The objective is to reuse the fibers in new, lower cost composites with similar properties. Starting from a pyrolysis step, followed by oxidation, an evaluation of the different parameters of the recycling process has been performed. The characterization of the fibers includes tensile tests, scanning electron microscopy, and Raman spectroscopy. The recycled fibers pre sented a reduction of their initial tensile strength lower than 10%. Then, remanufactur- ing of laminates using the recycled fibers was achieved by resin film infusion, obtaining laminates with properties similar to the brand-new composites. These results have the potential to be exploited by the automotive, aeronautical, wind energy, construction, and other sectors. significantly, independently of the oxidation time. These results still have to be investigated but are judged not to impact the properties of the remanufacture composites. the of the unidirection-ally aligned of film infusion method in of resulting ply thickness, disposition of the fiber/resin ratio, and porosity control. It provides a potential solution to prepreg production scraps with enhanced quality assurance, resulting in the reduction of toxic emissions. resulted lami nates presented similar content and shear properties as compared to the brand new composites.