Needle-shaped anticorrosion pigments based on the ferrites of zinc, calcium and magnesium

Purpose - This paper seeks to synthesize needle-shaped anticorrosion pigments based on the ferrites of Zn, Ca and Mg for metal protecting paints.Design methodology approach - Anticorrosion pigments were synthesized from oxides or carbonates at hot temperatures. The following pigments were synthesized: ZnFe2O4, MgFe2O4, CaFe2O4, Mg0.2Zn0.8Fe2O4, and Ca0.2Zn0.8Fe2O4. The prepared pigments were characterized by means of X-ray diffraction analysis, by measuring the distribution of particle size and by means of scanning electron microscopy. The synthesized anticorrosion pigments were used to formulate epoxy coatings with PVC = 10 per cent for the synthesized pigment and with the PVC CPVC ratio = 0.3. The coatings were tested for physical-mechanical properties and in corrosion atmospheres. The corrosion test results were compared with aluminium zinc phosphomolybdate.Findings - The needle-shaped particles were identified in the formulated pigments. It was found that all of the synthesized pigments had high anticorrosion efficiency comparable with that of Zn-Al phosphomolybdate. The needle-shaped particles markedly contributed to the advancement of the physical-mechanical properties of epoxy coatings.Practical implications - The synthesized pigments can be conveniently used in coatings protecting metal bases against corrosion.Originality value - The application of the synthesized pigments with the needle-shaped particles in anticorrosion paints protecting metals presents a new method. The benefit of the application and method of synthesizing anticorrosion pigments is that they do not contain heavy metals and are acceptable for the environment.