Anticorrosion efficiency of ZnxMgyAl2O4 core–shell spinels in organic coatings

Anticorrosion pigments were synthesized by reaction of metal aluminum lamellar particles whose surface is oxidized to Al2O3 during the first stage and by subsequent reaction with ZnO and/or MgO at 800–1150 °C producing a thin spinel layer that is chemically bonded to the metal core of the pigment particles. Core–shell spinels were synthesized: MgAl2O4/Al; Mg0.8Zn0.2Al2O4/Al; Mg0.6Zn0.4Al2O4/Al; Mg0.4Zn0.6Al2O4/Al; Mg0.2Zn0.8Al2O4/Al; and ZnAl2O4/Al. The prepared pigments were characterized by means of X-ray diffraction analysis and scanning electron microscopy. The synthesized anticorrosion pigments were used to prepare epoxy coatings that were tested upon application for their physical–mechanical properties, anticorrosion properties and resistance against a chemical environment. All of the synthesized pigments exhibit good anticorrosion efficiency in epoxy coatings. Compared to lamellar kaolin and metal core of aluminum without coverage, the protective function of the synthesized pigments in coatings is demonstrably better.