THE NEXT GENERATION OF ZINC-RICH PRIMERS

Together, these improvements could contribute to a significant decrease in operational costs over the life of the asset. Since zinc-rich primers are used extensively in the most corrosive environments, they represent a natural target for improvement via self-healing functionality. Design of Coating Systems and Electrochemical Characterization To assess the efficacy of self-healing functionality incorporated into zinc-rich primers for the corrosion protection of steel substrates, we started our evaluation by employing electrochemical characterization techniques to compare a commercially available SSPC Paint 20, Level 2 type coating (Figure 3a), with a version of the same coating incorporating AMPARMOR™ 2000, a self-healing additive based on the microencapsulation of an epoxy-based formulation (Figure 3b). [...]since less zinc is oxidized at the site of damage, the availability of and therefore the protection afforded by the un-oxidized zinc may be extendable over a longer duration. Furthermore, it appears that because the polymerized healing agent contributes to passivation and protection at the site of damage, the zinc present in the system is oxidized at a lower rate, presumably extending the sacrificial protection capability of the system over a longer period of time. * The incorporation of the self-healing additives at a loading of up to 4 wt.% had no effect on the open circuit potential suggesting that the connectivity of the zinc particles to each other and to the substrate was not affected by the presence of the self-healing additives. * With the incorporation of AMPARMOR 2000 into the zinc-rich primer, excellent adhesion maintenance and corrosion resistance was observed even on low-profile substrates such as lightly abraded CRS.