Anti-corrosion Property Of Flake Zinc Epoxy Coating Doped With Rare Earth In SRB

The zinc-rich epoxy coating with flake zinc as the main filler, E-44 epoxy and 651 polyamide curing agent as film former was prepared and modified by doping with rare earth chloride. Anti-bacterial properties, anti-corrosion properties, microstructure and mechanical properties of different zinc coatings and rare earth elements were tested by anti-SRB, EIS, SEM, XRD, EDS, scribe test, respectively.The results showed that lanthanum chloride and ytterbium chloride presented good anti-bacterial properties to SRB, and ytterbium chloride was better. Anti-SRB effect increased with concentration of rare earth increasing, but lanthanum oxide and ytterbium oxide showed no effect on SRB. The mechanical properties and anti-corrosion properties were best when the content of flake zinc was 25%(solid content was 67%, non-volatile zinc content was 37%), and flake zinc epoxy coating was better than commercial zinc-rich epoxy coating, but the anti-SRB properties for two kinds of coatings were weak. The anti-corrosion properties and anti-SRB properties of flake zinc epoxy coating doped with lanthanum chloride or ytterbium chloride were better than the coating without rare earth, especially ytterbium chloride coating.The analysis showed that SRB can be killed by the rare earth ions in solution. The growth and reproduction of SRB were effectively inhibited by rare earth ions which distributed on the surface of coating. Sulfide precipitation was obtained by the reaction between rare earth ions and metabolites of SRB, which can enhance the shielding effect of the coating and reduce the consumption rate of zinc. Flake zinc epoxy coating modified by rare earth can be used not only as primer or antirust coating, but also as anti-SRB coating alone.