Scientists recycle aircraft composite waste

Researchers at the National University of Singapore (NUS) have developed a method to recycle waste from carbon fiber and epoxy composites used in aircraft and other high-performance structures into aerogels. These aerogels can be employed for thermal insulation, sound absorption, and oil spill cleanup.

The study, led by Associate Professor Duong Hai Minh from the Department of Mechanical Engineering at NUS, was published in the journal Waste Management on June 29, 2026. Carbon fiber and epoxy composites are prevalent in aerospace, wind energy, automotive, and marine industries due to their lightweight and strong properties. However, the epoxy component, a thermoset polymer, poses recycling challenges as it cannot be remelted and reshaped.

Traditional recycling methods often focus on recovering carbon fibers, with epoxy resins typically destroyed or treated as low-value byproducts. These methods can also require high temperatures, strong chemicals, or significant energy. Duong's team innovatively utilized both carbon fiber and epoxy components by mechanically processing the composite waste into a fine powder and short fiber fragments, combining it with a cellulose-based binder, and freeze-drying the mixture to create an aerogel.

The freeze-drying process results in a sponge-like structure with tiny, connected pores, primarily composed of air, which reduces heat transfer. Laboratory tests demonstrated the aerogels' low thermal conductivity, indicating their potential as lightweight insulation materials.

"Our goal was to show that carbon fiber composite waste does not have to be treated only as a disposal problem," said Duong. "By using the whole material, including both the fiber and epoxy fractions, we can turn this waste stream into functional materials with higher value."

In addition to thermal insulation, the aerogels effectively absorbed sound, suggesting their use in sound-control applications. The aerogels also showed promise in environmental cleanup, as they could absorb large amounts of oil after being treated to repel water, indicating potential for oil spill cleanup and oil-water separation.

Tests with fibroblast cells confirmed that the aerogels were nontoxic under study conditions, supporting further exploration of their applications in human and environmental contexts. The team is seeking collaborations with partners in aerospace, advanced materials, manufacturing, and waste management sectors to scale up the technology and evaluate its environmental and economic viability for industrial use.

"Advanced composites have enabled lighter and more efficient structures in many industries," said Duong. "The next step is to ensure that these materials can be managed sustainably at the end of their service life."