The unique flake ZnAl alloy and OIT anti-corrosion and anti-mildew waterborne epoxy coatings

The purpose of this study is to improve the corrosion resistance of zinc rich epoxy coatings (ZRECs) by replacing Zn powders with ZnAl alloy powders, and to improve the biological corrosion resistance by adding 2-n-Octyl-4-isothiazolin-3-one (OIT). The special effect of ZnAl alloy powders in epoxy coatings was studied by electrochemical analysis and salt spray test. The samples before and after salt spray test were characterized by X-ray diffraction and Fourier transform infrared spectroscopy. The effects of different metal powders on the corrosion resistance of the coatings were considered. The surface and cross-sectional morphology of the coating were analyzed by SEM. The results show that the use of flake ZnAl alloy powders to replace Zn powders can reduce the pigment content by one-third. The ZnAl coatings and ZnAl@OIT coatings are denser than the Zn coatings, at the same time, the addition of OIT does not significantly reduce the coating impedance, but increases the mildew resistance of the coatings.