Researchers from the French National Center for Scientific Research (CNRS) and Safran Tech are developing a new type of resin designed to address material failures in electric aircraft engines. The project, based in Toulouse, focuses on using vitrimers to isolate electrical components within motors that operate under extreme thermal and mechanical stress.
The initiative is led by Marc Guerre, a chemist at the CNRS Softmat laboratory, and Gérald Lopez, a research and technology engineer at Safran Tech. Their work targets a specific challenge in aviation electrification: preventing cracks from forming in the resin insulation that encases copper wires inside electric motors.
Inside these motors, copper, aluminum, and resin coexist. As temperatures rise, potentially reaching 180 degrees Celsius, each material expands at different rates and speeds. These differential expansions create significant mechanical stress that can cause conventional resins to crack and fail. Lopez noted that the insulation must withstand extreme thermal, mechanical, and electrical constraints.
Lopez identified vitrimers as a potential solution due to their unique internal structure. Unlike standard thermosetting resins that become permanently rigid after manufacturing, vitrimers maintain dynamic mobility within their molecular network. When heated, these materials can flow slightly, allowing them to adapt to the shifting stresses of the motor environment.
The team has identified three key properties of vitrimers relevant to this application. First, the material’s ability to flow when heated allows it to close existing fissures. Second, the dynamic exchanges within the resin network help dissipate stress caused by differential expansion, preventing cracks from forming in the first place.
A third advantage involves end-of-life maintenance. Conventional resins make it difficult to recover copper from motors at the end of their service life. Vitrimer-based insulation can be degraded more easily, allowing metals like copper to be recovered intact and reused. This recyclability represents a significant economic benefit for the industry.
