Anticorrosive coating from mussel-inspired hyperbranched epoxy resin with high mechanical properties and corrosion resistance

The corrosion problem of metals has caused significant economic losses and safety risks in industrial production. Therefore, it is imperative to take measures to against corrosion. This study develops a new type of hyperbranched epoxy resin for anticorrosive coatings that contain catechol groups similar to mussels. The anticorrosive epoxy coating exhibits extremely high hardness and strength, outstanding thermal stability, excellent adhesion, as well as remarkable resistance to water and salt spray. The results of mechanical test showed that the tensile strength of the coatings could achieve as high as 63 MPa and their pencil hardness reached 8 H. After 30 days of immersion in saltwater, the pencil hardness could still keep 6 H, respectively. Furthermore, compared with the HBEP coating, the PCA-modified coating exposed to salt spray environment for 30 days shows less corrosion on both its surface and scratch area. This new type of coating has tremendous potential applications in areas such as marine metal protection. Graphical abstract