The influence of the critical pigment volume concentration (CPVC) on the properties of an epoxy coating. Part II. Anticorrosion and economic properties

The effect of the ratio of the pigment volume concentration (PVC) to the critical pigment volume concentration (CPVC), denoted hereafter by Λ, on the corrosion resistance properties of paint films has been investigated by ac impedance, potential-time measurements, cathodic disbonding and traditional accelerated tests. Painted mild steel electrodes were studied during exposure to 3.5% NaCl solution for up to 60 days. Paints based on epoxy resin were prepared at different Λ values (0.73, 0.80, 0.88, 0.93, 0.98, 1.08, 1.15 and 1.24). It is concluded that, for all systems, corrosion resistance can be affected greatly by the PVC/CPVC ratio and the conclusions offered by each of the techniques used are quite similar.