Investigation of the anticorrosion efficiency of ferrites Mg1−xZnxFe2O4 with different particle morphology and chemical composition in epoxy-ester resin-based coatings

• The ferrites were synthesised by the high-temperature solid-phase process.
• The ferrites were added to an epoxy-ester resin coating at PVC = 10 vol%.
• The ferrites with non isometric particles showed the anticorrosion efficiency.
• The non-isometric shape of the pigments enhances the mechanical paint properties.

Mixed metal oxides with the ferrospinel structure ZnFe2O4, Mg0.2Zn0.8Fe2O4 and MgFe2O4 were synthesised by the high-temperature solid-phase process. A series of pigments containing the metals Mg–Zn–Fe was prepared from 4 different starting iron oxides: viz. goethite (FeOOH), hematite (Fe2O3), magnetite (FeO·Fe2O3) and specularite (Fe2O3). The properties of the ferrites as pigments were examined in a solvent-based epoxy-ester resin-based coating material at a pigment volume concentration PVCferrite = 10%. The anticorrosion efficiency of the paints with the ferrites was examined by exposing panels coated with the paints to atmospheres with SO2, NaCl, or condensed moisture. Furthermore, the physico-mechanical properties of paint films containing the pigments were evaluated by standardised tests. Ferrites prepared from the needle-shaped FeOOH or lamellar Fe2O3 emerged as pigments with the best anticorrosion properties. From the aspect of chemical composition, the paint films containing Mg0.2Zn0.8Fe2O4, i.e. combinations of the cations Mg–Zn, were assessed as the best.