The effect of organotitanate-modified zinc oxide nanoparticles on some characteristics and anticorrosion protection properties of epoxy coating

Surface modification of metal oxide nanoparticles can enhance their dispersibility in polymer matrix. In this study, the zinc oxide (ZnO) nanoparticles (NPs) were organically modified by coupling agent as isopropyl tri (dioctyl phosphate) titanate (KR-12) with the initial content of 3 wt.% (in comparison with ZnO NPs weight). The characteristics of modified ZnO (m-ZnO) NPs, namely chemical changes, zeta potential, morphology, and thermal behavior, were evaluated using IR spectroscopy, DLS, SEM, and TGA methods, respectively. The obtained results suggested that ZnO NPs were modified successfully with KR-12 coupling agent. In comparison with the unmodified ZnO (u-ZnO) NPs, the m-ZnO NPs had additional functional groups and there were changes of some properties such as hydrophobic property, surface charge, and thermal stability of m-ZnO NPs. The m-ZnO NPs could disperse in epoxy resin better than the u-ZnO NPs. Therefore, the m-ZnO NPs improved the mechanical properties, chemical resistance, thermal stability, and anticorrosion protection ability of epoxy resin coating. The abrasion resistance and the adhesion of epoxy coating containing 2 wt.% m-ZnO NPs were increased about 40% and 54%, respectively. The bending resistance of epoxy resin was also enhanced, and the anticorrosion resistance of coatings was improved in the presence of m-ZnO nanoparticles.