Researchers with the Bio-Optimized Technologies to keep Thermoplastics out of Landfills and the Environment (BOTTLE) consortium have developed a simple, scalable process to recycle carbon fiber composites (CFCs) using hot acetic acid. The technique, detailed in Nature, promises to slash costs and energy consumption in reclaiming high-value fibers and chemicals from end-of-life composite products.

CFCs, widely used in bicycles, aircraft, and pressure vessels, are difficult to recycle due to their crosslinked epoxy-amine resins. The BOTTLE team discovered that hot acetic acid can cleave these tough chemical bonds, dissolving the resin into reusable building blocks while preserving the strength of recovered carbon fibers (rCF). In trials, reclaimed fibers were used to make new composites with more than double the strength-to-weight ratio of steel.

The cost of rCF could drop to just $1.50 per kilogram, dramatically lower than virgin fiber, and the process could also apply to glass fiber composites found in wind turbines and vehicles.

If we can scale this process and deploy it in the real world, we see no reason that whole panels on cars or trains couldn t be made of rCF composites instead of steel or aluminum, said Stephen Dempsey, a postdoctoral researcher at NREL and co-author of the study.

Funding came from the U.S. Department of Energy s Advanced Materials and Manufacturing Technologies Office, Bioenergy Technologies Office, and the University of Delaware s Center for Composite Materials.

Source: www.nrel.gov