Robust coating for high-temperature and corrosion-resistant

Polysilazane (PSZ) is a class of novel materials with significant advantages; however, its practical applications are severely limited due to drawbacks such as the need for high-temperature curing and susceptibility to brittleness and cracking. Consequently, we have chosen PSZ and epoxy resin (EP) as the film-forming resins, with silica aerogel (SiO2gel) serving as the inorganic filler, to fabricate a SiO2gel–PSZ/EP composite coating capable of curing at room temperature. The incorporation of EP and SiO2gel has improved the toughness, mechanical stability, and thermal stability of PSZ. After 800 cycles of abrasion wear, the composite coating maintained its surface integrity. The scratch test rated its adhesion at level 1. Additionally, after 14 days of immersion in acidic and alkaline solutions, the coating demonstrated favorable chemical stability. The coating underwent 10 cycles of thermal shock testing, during which no significant cracking or peeling was observed on the surface. Finally, electrochemical impedance spectroscopy testing revealed that, after exposure to 300 °C, the composite coating exhibited a corrosion current density of 1.23 × 10−10 cm2, corresponding to a corrosion protection efficiency of up to 99.99%. In summary, the coating maintains excellent anticorrosion properties even after exposure to high temperatures and demonstrates outstanding stability, significantly enhancing its durability in harsh environments. This enhancement suggests a broad potential for applications in the field of subsea transportation.