A Washington State University (WSU) research team has reportedly developed a new way to recycle carbon fiber. In their project, Jinwen Zhang, a professor in the school of mechanical and materials engineering, and his team developed a new chemical recycling method that used mild acids as catalysts in liquid ethanol at a relatively low temperature to break down the thermosets. In particular, it was the combination of chemicals that proved effective, says Zhang. To break down cured materials effectively, the researchers raised the temperature of the material so that the catalyst-containing liquid can penetrate into the composite and break down the complex structure. Zhang used ethanol to make the resins expand and zinc chloride to break down critical carbon-nitrogen bonds.
“It is critical to develop efficient catalytic systems that are capable of permeating into the cured resins and breaking down the chemical bonds of cured resins,” he says.
The researchers were able to preserve the carbon fiber as well as the resin material in a useful form that could be re-used. They have filed for a patent and are working to commercialize their methods.
The work was funded by the Joint Center for Aerospace Technology Innovation (JCATI) in collaboration with industry partner, Global Fiberglass Solutions. In addition to Zhang, researchers on the project included Junna Xin, assistant research professor, Tuan Liu, postdoctoral research associate, and graduate student Xiaolong Guo.