Mussel-Inspired and Silane Comodification of MoS2–TiN Hybrid Fillers for Enhanced Thermal, Mechanical, and Tribological Properties in Epoxy Resin

Improving the dispersion and compatibility of fillers in epoxy resin (EP) is crucial for enhancing the thermal stability, mechanical properties, and tribological performance of coatings. This study presents a novel biomimetic modification strategy. MoS2–TiN hybrid fillers are uniformly dispersed in the EP matrix and strongly bonded through comodification with polydopamine (PDA) and γ-aminopropyltriethoxysilane (KH550). The successful synthesis of MoS2–TiN@(PDA+KH550) fillers is confirmed by using Fourier transform infrared spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. Scanning electron microscopy, transmission electron microscopy, and dispersion tests show that the aggregation of MoS2 and TiN is alleviated. Compared to pure EP, the PDA@MoS2–KH550@TiN (2:1)/EP (PMT2@EP) coating shows significant improvements in several aspects. In terms of thermal stability, the residual carbon rate at 800 °C increased from 9.38 to 11.98%. For mechanical properties, the storage modulus increased by 7.2%, the glass transition temperature (Tg) increased by 24.6%, the tensile strength increased by 42.1%, the tensile modulus increased by 60.9%, the hardness increased by 58.3%, and the flexural strength increased by 59.1%. Additionally, the coating exhibits enhanced tribological performance, with a reduction in the friction coefficient of 81.8% (from 0.555 to 0.101) and a decrease in the wear rate of 77.8% (from 11.64 × 10–5 mm3/(N m) to 2.58 × 10–5 mm3/(N m)). This biomimetic interface design provides important experimental and technical support for developing high-performance, wear-resistant, low-friction EP coatings.