Upcycling decommissioned wind turbine blades into high-performance engineering wood composites

The disposal of end-of-life Glass Fiber Reinforced Polymer (GFRP) from wind turbine blades poses a critical environmental challenge, demanding sustainable upcycling solutions and practical utilization. However, unlocking its reinforcement potential is fundamentally crippled by the chemically inert, low-adhesion epoxy surface, a barrier that has precluded its effective use in high-performance composites. Herein, we introduce a scalable and cost-effective strategy to upcycle this problematic waste into high-performance, multifunctional engineering wood composites (EWC) by overcoming this critical interfacial barrier. A custom-designed mechanical modification process was developed to activate the GFRP surface, creating a rough, porous, and highly wettable interface by selectively removing the inert epoxy resin layer. The optimized EWC-40 composite, incorporating 40 % modified GFRP, demonstrated a remarkable synergy of properties, including a flexural strength (90.47 MPa) and internal bonding strength (1.56 MPa) that vastly surpass those of conventional wood panels. Crucially, the composite also exhibited superior fire safety, with a 26.5 % reduction in the peak heat release rate (pHRR) and a 45 % reduction in total smoke production (TSP). Furthermore, it demonstrated outstanding durability, not only retaining excellent mechanical integrity after aggressive accelerated aging cycles but also achieving the highest durability rating (Class I) in a decay resistance assay with 83.2 % less mass loss than the control. This study establishes a cost-effective and industrially viable pathway for upcycling GFRP waste into superior structural materials and, more broadly, demonstrates that targeted mechanical activation is a powerful platform technology for valorizing a wide range of challenging thermoset composite wastes.