Advanced Examination of Zinc Rich Primers with Thermodielectric Spectroscopy

Zinc-rich primers (ZRPs) are widely used coatings for corrosion control on steel surfaces. Usually ZRPs use high zinc concentration in the paint and a little amount of organic resin used as a binder. Commonly, two fundamental protection mechanisms operating in ZRPs can be recognised, namely the galvanic protection and the barrier effect. The high zinc content can secure cathodic protection to the base metal, and the zinc corrosion products can make the barrier effect. In this research study, the cathodic corrosion protection capabilities of zinc rich alkyd primers prepared with different spherical zinc dust volume concentrations (0-20-40-60-80% by weight) are tested. The mechanical, electrochemical and dielectric properties are measured in order to find a correlation between these and the protection capabilities of the coating.