High solids organic-inorganic hybrid coatings based on silicone-epoxy-silica coating with improved anticorrosion performance for AA2024 protection.

• Efficient high-solids, one-coat paints were synthesized for AA2024 through sol-gel method. • Strong chemical interaction with enhanced cross-linking density can be achieved in silicone-epoxy-silica coating. • The hybrid coating presented an impedance modulus of GΩ after 628 h immersion with a thickness of less than 20 μm. • Char residue of the hybrid coating was increased to more than 40% by the addition of HTEOS to silicone-epoxy coating. • The high solids hybrid coating displayed improved impact resistance and good flexibility. A hybrid organic-inorganic coating was prepared with silicone-epoxy coating and prehydrolyzed TEOS (HTEOS) through the sol-gel process. This study aimed to study the effect of HTEOS on the corrosion protection performance of hybrid coatings on AA2024 alloy. The obtained hybrid coatings were characterized by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and water contact angle tests. The impact resistance of the coatings was estimated by the cupping test. Electrochemical impedance spectroscopy (EIS) and scanning vibration electrochemical technology (SVET) tests were used to evaluate the corrosion resistance of the hybrid coating. With the presence of 4 wt% HTEOS, the hybrid coating showed better corrosion resistance and impact resistance. The superior protection of the hybrid coating with 4 wt% HTEOS could be attributed to the enhanced Si O Si network and higher proportion of the inorganic phase. [ABSTRACT FROM AUTHOR]