Wind turbine blade epoxy upcycled into high strength adhesives via mild catalytic oxidation

A new study published in Engineering demonstrates a mild catalytic oxidation approach that converts epoxy resin from end‑of‑life wind turbine blades into high‑performance adhesives, offering a sustainable pathway for the recycling of thermoset composite waste. The research, conducted by a team from Sichuan University, introduces a catalytic system that selectively breaks C–O bonds in epoxy resin under moderate conditions, enabling full utilization of degraded products and efficient recovery of both catalysts and reinforcing fibers.

Epoxy resin, the dominant matrix in wind turbine blade composites, features a stable three‑dimensional crosslinked structure that is insoluble, non‑melting, and resistant to natural degradation, creating challenges for conventional recycling. Existing chemical methods often involve harsh conditions, low product value, or limited catalyst reuse. In the newly reported system, vanadyl acetylacetonate, VO(acac)₂, serves as the catalyst with molecular oxygen as the oxidant. The team shows that using just 4 wt% catalyst, epoxy resin can be completely degraded at 100 °C within 6 h. The process selectively cleaves C–O bonds while preserving benzene rings and C–N bonds, generating hydroxy‑rich degraded products.

A key advantage of this method is that the degraded products can be directly and fully used as adhesives without additional modification. These upcycled materials exhibit strong bonding performance across metals, glass, wood, and various plastics, with stable adhesion in acidic, alkaline, and common organic solvent environments. The degraded products also demonstrate convenient removability using ethanol without damaging substrate surfaces. Beyond resin upcycling, the technique supports the recovery of reaction solvents, catalysts, and glass or carbon fibers from composites. The recovered catalyst maintains stable performance through multiple cycles, and the retrieved fibers retain clean surfaces and high mechanical integrity, with tensile strength retention close to that of virgin fibers.

This closed‑loop recycling strategy addresses both the disposal crisis of wind turbine blade waste and the demand for high‑value upcycling of thermosets. By combining mild reaction parameters, selective bond cleavage, and full component recovery, the method supports the low‑carbon circular development of the wind power industry while providing a scalable route for designing high‑strength adhesives from waste polymer sources. The findings contribute to more sustainable management of composite materials and expand the portfolio of cost‑effective, eco‑friendly recycling technologies for crosslinked polymers.

The paper “Upcycling of Epoxy Resin in Wind Turbine Blades into High-Strength Adhesives,” is authored by Chuanchuan Zhao, Xiang-Xin Xiao, Xinhao Chang, Shimei Xu, Xuehui Liu. Full text of the open access paper: https://doi.org/10.1016/j.eng.2026.02.011. For more information about Engineering, visit the website at https://www.sciencedirect.com/journal/engineering.