Recycling Glass Fiber from Polyurethane Composite by Pyrolysis Strategy with High Mechanical Properties

With the rapid advancement of the wind power industry, the recycling of retired wind turbine blades and the regeneration of glass fibers have become urgent environmental and economic issues. In this article, a two-step pyrolysis strategy was put forward, in which the relationship between the pyrolysis parameters and the properties of the recycled glass fibers, including the surface morphology, defects, and mechanical properties were demonstrated. We found that pyrolyzing the composites at 500°C under high-temperature water vapor atmosphere to recover the glass fibers, and oxidizing at 450°C to remove the residual carbon of fibers is the optimal choice. In this way, not only can the fibers be recovered from the waste composites, but also the mechanical properties of the fibers can be retained while removing the residual carbon on the surface, which provides a guarantee for subsequent high-value reuse of waste fan blade composite materials.