Titanium-boron co-doped organic-inorganic hybrid coatings with enhanced anticorrosion performance

Complex marine environments (high salinity, humidity, and temperature) accelerate material degradation, urgently demanding durable coatings with integrated thermal stability and corrosion protection. Currently, phenolic epoxy resins are widely used in marine environments for their excellent corrosion resistance, but their long-term durability is insufficient. In this study, phenyltriethoxysilane (PTES), dimethyldiethoxysilane (DEMS), isopropyl titanate (TPT), and boric acid are employed as functional precursors to synthesize a cross-linked titanium-boron-containing organosilicon resin (TBS) via a facile sol-gel process. The resin is subsequently incorporated into a phenolic epoxy resin (EPN) matrix as a functional modifier, constructing a composite protective system of titanium‑boron co-doped organic-inorganic hybrid coatings with synergistically enhanced anticorrosion performance. The results of the electrochemical impedance spectroscopy (EIS) test show that the hybridized coatings exhibits superior anticorrosive performance when the mass fraction of TBS is 50 %. The low-frequency impedance (|Z|_{0.01 Hz}) remains above 10¹⁰ Ω·cm² after 30 days immersion in 3.5 wt% NaCl solution. In addition, the TBS₁-EPN₁ coating retains the most intact surface after 7 days of immersion in acid/alkali solutions. Meanwhile, the heat resistance of the coating is optimized, with the initial decomposition temperature increases to 233 °C. This study provides an excellent strategy for designing high-performance anticorrosion coatings for marine hydrothermal areas.