Effect of high-temperature mechanochemistry method modified TiO2 on the dispersibility and corrosion resistance of TiO2-epoxy coatings

Abstract

Purpose The purpose of this paper is to enhance the compatibility of titanium dioxide in epoxy resins and thus the corrosion resistance of the coatings. Design/methodology/approach In this work, TiO 2 was modified by the mechanochemistry method where mechanical energy was combined with thermal energy to complete the modification. The stability of modified TiO 2 in epoxy was analyzed by sedimentation experiment. The modified TiO 2 -epoxy coating was prepared, and the corrosion resistance of the coating was analyzed by open circuit potential, electrochemical impedance spectroscopy and neutral salt spray test. Findings High-temperature mechanical modification can improve the compatibility of TiO 2 in epoxy resin. At the same time, the modified TiO 2 -epoxy coating showed better corrosion resistance. Compared to the unmodified TiO 2 -epoxy coating, the coating improved the dry adhesion force by 61.7% and the adhesion drop by 33.3%. After 2,300 h of immersion in 3.5 Wt.% NaCl solution, the coating resistance of the modified TiO 2 coating was enhanced by nearly two orders of magnitude compared to the unmodified coating. Originality/value The authors have grafted epoxy molecules onto TiO 2 surfaces using a high-temperature mechanical force modification method. The compatibility of TiO 2 with epoxy resin is enhanced, resulting in improved adhesion of the coating to the substrate and corrosion resistance of the coating.