Hybrid ZrO2/Cr2O3 Epoxy Nanocomposites as Organic Coatings for Steel

Abstract

Mixed ZrO2 and Cr2O3 nanoparticles (NPs) were prepared using a liquid phase chemical technique and applied as reinforced filler for epoxy coatings with different weight ratios ranged from 0.5 to 2.5 wt.% to protect carbon steel from corrosion. The ZrO2/Cr2O3 NPs were used to catalyze the curing of the epoxy composite films to modify their mechanical and thermal characteristics on the steel surface. The crystalline structure, particle sizes, and surface morphologies of the prepared ZrO2 and Cr2O3 NPs were characterized to investigate their chemical composition and dispersion. The thermal stability of epoxy ZrO2/Cr2O3 coating films was investigated by thermogravimetric analysis (TGA), and the mechanical properties of the cured epoxy films were also studied. The dispersion of the Cr2O3/ZrO2 NPs into the epoxy matrix was investigated by scanning electron microscope (SEM), dynamic mechanical analysis (DMA) and TGA analyses. The results of salt spray test, used to investigate the anticorrosion performance of the epoxy coatings) were combined with thermal characteristics to confirm that the addition of Cr2O3/ZrO2 NPs significantly improved the corrosion resistance and the thermal stability of epoxy coating. The mechanical properties, adhesion, hardness, impact strength, flexibility and abrasion resistance were also improved with the addition of ZrO2/Cr2O3 NPs filler content.