Synthesis of Mn-MOFs loaded zinc phosphate composite for water-based acrylic coatings with durable anticorrosion performance on mild steel

A new metal-organic framework (MOF) compound [Mn2(2,2'-bca)2(H2O)2] n (Mn-MOFs) was successfully synthesized by solvothermal method, and Mn-MOFs@Zn material was prepared by loading zinc phosphate onto Mn-MOFs by ball milling, then Mn-MOFs@Zn was added to the water-based acrylic paint to prepare Mn-MOFs@Zn@acrylic coating. The AC impedance test results showed Mn-MOFs@Zn@acrylic coating has higher corrosion inhibition performance and stability to mild steel when compared with blank coating. The impedance modulus of the blank coating in the low frequency region decreased by 90%, and the R ct showed a trend of first increasing and then decreasing over time, the maximum R ct was only 303.8 Ω, which was only Mn-MOFs@Zn@acrylic coating one-seventh of the R ct value. The artificial scratch experiment showed that the Mn-MOFs@Zn@acrylic coating only slightly corrodes at the scratches, because Mn-MOFs@Zn material made the coating a self-repairing function and improved the durable anticorrosion performance of the acrylic coating.