Researchers at Washington State University may have found a way to recycle expensive carbon fiber plastics that are used in almost everything from airplanes to wind energy.
The research, appearing in Polymer Degradation and Stability, details how to re-use the typically hard to recycle carbon fiber plastic.
Because carbon fiber plastic components (for instance, in airplanes) are thermosets, they are cured and nearly impossible to undo or return to their original material. Grinding or breaking down the material with caustic chemicals to retrieve the carbon fiber also proved unsuccessful by damaging the carbon fiber in the process or creating additional waste disposal problems.
Jinwen Zhang, a professor in the School of Mechanical and Materials Engineering, and his team developed another chemical recycling approach using mild acids as catalysts in liquid ethanol at a relatively low temperature to break down the thermosets. The combination of chemicals proved effective, said Zhang. In order to effectively break down cured materials, the researchers raised the temperature of the material so that the catalyst-containing liquid could penetrate the composite and break down the complex structure. Zhang used ethanol to make the resins expand and the zinc chloride to break down the critical carbon-nitrogen bonds. The carbon fibers were preserved and able to be re-used.
The research team has filed for a patent and are attempting to commercialize the new approach.