Fabrication and performance of high-density polyethylene based composites enhanced by the synergistic Integration of recycled wind turbine blade fibers and wheat straw fibers

With the large-scale decommissioning of wind turbine blades, the resource utilization of these discarded blades has garnered significant attention. This study utilizes recycled wind turbine blade recycling fibers (RWRF) and wheat straw fibers (WSF) as reinforcing components, with high-density polyethylene (HDPE) as the matrix, to fabricate fiber-reinforced resin-based composites through melt blending and injection molding techniques. RWRF was modified using dopamine (DA), γ-mercaptopropyl trimethoxysilane (KH590), and silicon carbide whiskers (SiCw). The results indicate that RWRF contains 73.87 % glass fibers (GF), with aspect ratios of 52.69 and 13.51 for RWRF and WSF, respectively, and that RWRF/HDPE composite exhibits a lower water absorption rate compared to WSF/HDPE composite. The optimal fiber mixing ratio is R20W10, with superior performance observed when RWRF is added first in RWRF/WSF/HDPE preparation. Modification with 0.5 % KH590 yields the greatest improvement in mechanical properties, while DA modification results in the lowest saturated water absorption rate of 2.2 %. Post-modification, both the maximum decomposition temperature and residual mass of RWRF/WSF/HDPE are enhanced. This paper represents the first systematic exploration of the feasibility of synergistically reinforcing thermoplastic resin-based composites with end-of-life (EoL) wind turbine blade fibers and wheat straw fibers, providing a significant theoretical basis for the application of EoL wind turbine blades in plant fiber-reinforced composites.