Mild chemical recycling of waste wind turbine blade for direct reuse in production of thermoplastic composites with enhanced performance

Abstract

The increasing use of glass fiber-reinforced plastics (GFRP) in wind turbine (WT) blades poses significant recycling challenges. This study presents a mild chemical recycling method for WT GFRP waste, where the recyclates were repurposed to enhance the mechanical performance of thermoplastics. Specifically, WT GFRP waste was decomposed in aqueous solutions at temperatures ≤ 250 °C, achieving a degradation degree of up to 83.5%. The recycled GFRP (rGFRP), containing reclaimed glass fiber and decomposed matrix polymer, was directly compounded with commercial thermoplastics to produce fiber-reinforced composites. These rGFRP-reinforced thermoplastics exhibited superior mechanical properties, with tensile strength and modulus increasing from 40.4 MPa and 1.5 GPa for neat PA6 to 131.3 MPa and 15.5 GPa for composites containing 70 wt% rGFRP. This work offers a straightforward, environmentally friendly approach to recycling WT GFRP waste, providing a promising pathway for the high-value utilization of waste polymer composites.