Reuse of Wind Turbine Blades for High-Performance Flame-Retardant Epoxy Composites via Surface Modification

With the rapid development of clean and renewable energy sources, particularly wind energy, the recycling of wind turbine (WT) blades has emerged as a significant challenge in addressing environmental impacts. In this study, a novel flame retardant, designated as Fr@WGE@PDA, was synthesized by using recycled fine powder from WT blades. The synthesis was accomplished using polydopamine (PDA) as the interlayer and hexachlorocyclotriphosphazene (HCCP) as the primary raw material via a two-step process. The successful fabrication of Fr@WGE@PDA was confirmed via multiple characterizations. The incorporation of Fr@WGE@PDA significantly enhanced the flame retardancy of the epoxy (EP) composites. Notably, the enhancement was achieved without significantly compromising the mechanical properties of the composites. The EP composite incorporated with Fr@WGE@PDA at a loading level of 20 wt % exhibited a tensile strength of ∼69.4 MPa and an elongation at break of ∼6.6%. Additionally, the EP composite achieved a limiting oxygen index (LOI) of 31.9% and a UL-94 V-0 rating. Based on analyses of both the gas phase and condensed phase, a degradation mechanism for the EP composite was proposed. This study presents a sustainable strategy to recycle WT blades into an efficient flame retardant, offering promising prospects for both fundamental research and practical applications.