Effect of zinc oxide in combating corrosion in zinc-rich primer

During the production of zinc pigments, some zinc may get oxidized and remains as impurity. In the present study, the effect of spherical ZnO on corrosion protection properties was evaluated along with lamellar zinc. ZnO was added in various weight fractions in epoxy primer coating at 60% PVC. The coated panels were evaluated among others for their conductance, packing density and morphology. The corrosion resistance was measured using salt spray test for 3000 h of exposure. Open circuit potential (i.e. corrosion potential) was measured in 3.5 wt.% NaCl salt solution. The best corrosion protection was obtained with 15 wt.% of ZnO.