The bond‐forming wet modification of two‐dimensional Mg(OH)2 nanoflakes by silane coupling agent for EVA resin with enhanced performance

Abstract Ethylene Vinyl Acetate (EVA) has been widely used in various industries for its excellent flexibility and corrosion resistance. However, its high flammability poses significant safety risks, necessitating the incorporation of flame‐retardants to improve its fire resistance. This study focuses on the wet surface modification of magnesium hydroxide (MH) using n‐octyl triethoxysilane (OTES). The hydrolysis products of OTES react with the OH on the MH surface to form SiOMg bonds, thereby enhancing the surface hydrophobicity and compatibility with EVA. MMH was incorporated into EVA, and the resulting composites were characterized using XRD, SEM, TG, BET, FT‐IR, and XPS. The optimal modification conditions were achieved with an OTES dosage of 3 wt% at 45 °C for 60 min, yielding a contact angle of 142°, an activation index of 98.12%, and an oil absorption rate of 43 mL/100 g. The EVA/MMH composites demonstrated superior thermal stability and flame retardancy compared to unmodified EVA. Specifically, the limiting oxygen index (LOI) of EVA/MMH‐55 reached 34.9%, and it achieved a UL‐94 V‐0 rating, indicating excellent self‐extinguishing properties. This study provides a novel approach for the surface modification of MH, offering a practical solution to enhance the flame retardancy and thermal stability of EVA composites. Highlights Hydrophobic MMH is obtained by wet surface coating modification of MH by OTES. Contact angle of MMH is 142° under optimal modification conditions (60 min, 45 °C and 3 wt%) The chemical reaction process between OTES and the MH surface has been analyzed, revealing the mechanism by which the SiOH groups on OTES react with the OH groups on the MH surface to form SiOMg bonds, which intertwine to form a hydrophobic layer. The specific surface area of MMH is reduced, and it has good compatibility with EVA resin. The LOI of EVA/MMH‐55 is 34.9%, making it a nonflammable material.