Abstract: 　　The long-term integrity of oil storage and transportation equipment is confronted with severe challenges posed by the synergistic effects of impact damage and environmental corrosion. To address this issue, a novel multifunctional polyurea coating integrating high impact toughness, excellent corrosion resistance and intrinsic flame retardancy was prepared via a multi-scale design strategy in this study. It can be applied to the surfaces of transmission pipelines, above-ground storage tanks and fuel tanks of mobile equipment for reinforcement and corrosion protection purposes.
　　Through formula regulation, the synergistic design of rigid-flexible chain segments was realized, and the molecular structure was optimized, thus achieving a favorable balance between high tensile strength (>31.0 MPa) and high elongation at break (>390%). The introduction of a solid-liquid composite flame-retardant system endowed the material with B1-grade flame retardancy without significantly impairing its mechanical properties. In addition, the incorporation of 0.5 wt% functionalized graphene nanosheets constructed a dense physical barrier, which remarkably enhanced the corrosion resistance of the coating. After immersion in 10% H₂SO₄, 10% HCl, 20% NaOH and 10% NaCl solutions for 30 days, the strength retention rate of the coating remained above 85% in all cases.
　　Results from the Split Hopkinson Pressure Bar (SHPB) dynamic mechanical analysis and full-scale fuel tank impact tests demonstrated that the coating exhibits outstanding energy absorption capacity and structural integrity maintenance capability under high strain rate loading. This study provides an effective solution for the protection of oil storage and transportation equipment under harsh working conditions.