Surface modification of cast iron slag with rare earth coupling agent enhances mechanical and thermal properties of nonwoven geotextile trimmings-based composite plate

This study aims to explore a novel approach to rationally utilize nonwoven geotextile trimmings (NWGT) and cast iron slag (CIOS) for preparation of composite plate, in which NWGT was acted as an organic matrix and CIOS was treated as an inorganic filler. Furthermore, a rare earth coupling agent (WOT-108) was employed to modify CIOS particles surface. The characterization results show that the rare earth coupling agent successfully attaches to the CIOS surface, improving the dispersion and hydrophobicity of CIOS, and enhancing the interfacial compatibility between the modified-CIOS (mCIOS) and the NWGT matrix. Consequently, the mechanical performance and thermal properties of mCIOS/NWGT composites are holistically strengthened. The mCIOS/NWGT composites show 51.8 % and 20.3 % increase in tensile strength, and 94.9 % and 27.1 % enhancement in flexural strength compared to pure NWGT and CIOS/NWGT composites, respectively. Notably, the addition of the rare earth coupling agent results in a 52.3 % improvement in the impact strength of mCIOS/NWGT composites, which is a significant finding. Moreover, the addition of CIOS and coupling agent modification significantly enhance the thermal conductivity and thermal stability of composites. The preparation of mCIOS/NWGT composites with excellent mechanical performance and thermal properties provides an innovative approach to the utilization of solid wastes, achieving an environmentally friendly and cost-effective manufacturing process.