Georgia Tech’s Research Horizons magazine reports that researchers at Georgia Tech have developed a method to recycle nearly 100 percent of the materials in certain types of thermoset carbon fiber composites. During the new process, the carbon fiber composites are soaked in alcohol, which slowly dissolves the epoxy that binds and gives shape to the carbon fibers. Once dissolved, the researchers can separate the carbon fibers and the epoxy and use them for new applications.
“This method we think could have a lot of immediate industrial applications, with lots [of] economical and environment benefits,” said Kai Yu, a postdoctoral researcher at Georgia Tech and now an assistant professor at University of Colorado Denver.
Jerry Qi, a professor at Georgia Tech’s George W. Woodruff School of Mechanical Engineering, said traditional carbon fiber has historically presented a number of challenges for recycling.
“The polymer matrix is usually crosslinked, just like the rubber, and it can’t be simply melted; it’s very hard to strip away the polymer to reclaim the embedded carbon fibers, which are more valuable to recycle,” Qi said.
According to Georgia Tech, the research team focused on carbon fiber that uses a special type of epoxy called “vitrimer epoxy” to give the composite component its shape.
“Vitrimers contain dynamic bonds that can alternate their structure without losing network integrity under certain conditions,” Yu said. “We let alcohol, which has small molecules, to participate in the network of alternating reactions, which effectively dissolved the vitrimer.”
Qi says the new recycling process has the potential to reduce the thousands of tons of carbon fiber waste generated each year in the United States and Europe. Yu added that the process is that it’s simple and straightforward.
“It’s very easy to operate, so there’s no limit to the size,” Yu said. “It can be easily scaled up.”