Manufacturing of robust adhesive through synergistic co-upcycling of epoxy-glass fiber components from end-of-life wind turbine blades

The high-value recycling of waste wind turbine blades not only mitigates environmental pollution but also advances resource circularity, but the current recycling approaches predominantly focus on the segregated recovery of degraded products and fibers, in which a fundamental challenge lies in reconciling high-quality fiber recovery with value-added utilization of degraded products. Furthermore, the practical application of the recycled fibers is constrained by size and structure limitations. Herein, we developed an innovative strategy for synergistic co-upcycling of fiber and degraded products through one-pot catalytic oxidation approach. Under the joint action of oxygen and only 4 wt% vanadium catalyst, the C O bond in epoxy resin (EP) is selectively cleaved to yield hydroxyl-rich degraded products (DEP), the fibers are simultaneously oxidized and modified. By integrating DEP and modified fibers in situ, a strong and tough adhesive (DEP-RGF) is obtained, its adhesion strength and fracture displacement on wood are 5.30 MPa and 1.44 mm, respectively, both parameters doubling those of pure DEP. Notably, the adhesive performances of DEP-RGF are better than that of the composite fabricated by mixing DEP with original fibers. Furthermore, DEP-RGF also exhibits strong adhesion to diverse substrates such as metal, plastics and glass, achieving a maximum adhesion strength of 10.86 MPa. This simple and efficient recycling method not only offers a viable solution for the sustainability of wind energy technologies, but also provides valuable insights into the upcycling of other types of mixed plastics.