Plant-based epoxy enables recyclable carbon fiber

In Colorado, 10 times stronger than steel, nearly half the weight of aluminum, far stiffer than fiberglass—carbon fiber carries a package of advantages, yet is expensive and still needs perfecting to become economical for mass market vehicles. But thanks to NREL researchers and advances in biobased material design, recycling carbon fiber at an industrial scale could be close at hand.

Through a project supported by the U.S. Department of Energy’s Vehicle Technologies Office, under the Composites Core Program, Rorrer and other NREL researchers have shown that making carbon fiber composites with bio-based epoxies and an anhydride hardener makes the material fully recyclable by introducing linkages that are more easily degraded. In fact, the recycling process—called methanolysis—can be selectively triggered at room temperature without degrading the quality or orientation of the fibers. That could represent a strong step toward a circular material, which can make carbon fiber cheaper and greener when used across multiple lives.