Synergistic enhancement of corrosion and wear resistance in polyurethane composite coatings using modified molybdenum disulfide and silicon carbide nanocomposites

Polyurethane (PU) coatings, extensively used for metal surface protection, face limitations in harsh environments due to their insufficient wear resistance. A novel PU composite coating system, synergistically reinforced with modified molybdenum disulfide (MoS 2 ) and silicon carbide (SiC) nanoparticles, was developed to enhance both corrosion and wear resistance. By modifying MoS 2 via the silane coupling agent (KH560)-polydopamine (PDA) cross-linking, a dense network was formed to block corrosive agents, while dispersed SiC nanoparticles optimized stress distribution and reduced surface friction. The composite coating containing 10 wt.% SiC (KPM-10S/PU) demonstrates comprehensive performance, exhibiting 342 times higher impedance compared to the pure PU, 79% reduction in the wear loss volume against 316L steel, and outstanding resistance in HNO 3 and salt spray tests. Although 15 wt.% SiC (KPM-15S/PU) achieved the highest initial impedance and the lowest friction coefficient, excessive SiC compromised matrix compatibility, increasing corrosion vulnerability. This work elucidates the corrosion blocking and wear inhibition reinforcement mechanism of MoS 2 -SiC composite, and provides a scalable strategy for designing multifunctional coatings in demanding environments of marine infrastructure.