Influence of nano-SiO₂ particle compositing on the anti-corrosion performance of polyurea coatings

The light aging performance of nano-SiO₂ particle composited polyurea coatings were tested by ultraviolet accelerated aging and surface morphology observations.The corrosion resistance to seawater of the coatings was measured by soaking in a 3.5% NaCl solution.Field emission scanning electron microscopy,corrosion potential measurements and electrochemical impedance spectroscopy(EIS) were used to analyze the corrosion resistance of different coatings.The results indicate that the corrosion resistance of aromatic polyurea coatings increases significantly by compositing the nano-SiO₂ powder.After the compositing,the corrosion potential improves from-40 mV to 60 mV,the EIS modulus increases approximately one magnitude,the accelerated aging stage delays about 120 h,and the life of the coatings in the 3.5% NaCl solution increases by 600 h roughly.