IKBFU demonstrates possibility of recycling and repurposing carbon fiber from composites

MOSCOW, May 24. /TASS/. Scientists from Immanuel Kant Baltic Federal University (IKBFU, Kaliningrad), Kemerovo State University and Perm National Research Polytechnic University demonstrated the possibility of recycling and repurposing carbon fibers and fabrics from composites used in different branches: aviation, rocket production, motor industry and others, the press service of the university announced. The overwhelming majority of polymer composite materials consists of the carbon fiber and thermosetting resins (usually based on epoxy and formaldehyde resins) that provides chemical, thermal and mechanical stability of the material. As the use of composites is expected to increase, for example in the aerospace, automotive and construction industries, it is important to find a solution to deal with the growing volume of carbon fiber waste. Currently, most polymer composites are sent to landfills. However, the lack of carbon fiber recycling technologies may slow down its widespread use in the future, which makes the task of finding technologies to reclaim carbon fibers from composites to repurpose them urgent. "The novelty of the work lies in reclaiming and using carbon fibers from carbon plastic based on phenol-formaldehyde resin, as the available studies are mainly devoted to the extraction of fibers from composites based on epoxy resins," the press service noted. The purpose of the study was to research the recycling process of polymer composites based on phenol-formaldehyde resins using the solvolysis method, which uses a special solvent: supercritical water, alcohols and oxidants as the medium for depolymerization of the resin and the release of the fibers. "This approach generally requires moderate temperatures (from room temperature to 400 degrees Celsius), which makes it possible to obtain monomers and fibers of high quality," the press office quotes Yulia Kulikova, a researcher from the Institute of Living Systems at IKBFU and one of the authors of the work, as saying. According to Yulia Kulikova, among the advantages of chemical methods are low power input, high efficiency of resin removal (90-98%) and retention of properties of reinforcing fibers. The solvolysis method has a lower environmental impact compared to other carbon plastic processing technologies. "In the course of the research we have demonstrated high quality and promising potential of repurposing the reclaimed secondary fibers to the resource cycle, including for reinforcement of concrete and production of composite materials", Kulikova pointed out. Read more