Effect of nano-ZnO particles on the corrosion behavior of alkyd-based waterborne coatings

A nano-composite was formed by incorporating nano-ZnO in a specially developed alkyd-based water-borne coating to different loading levels. The nano-ZnO based composite coatings were applied on mild steel substrate by dipping. The coated panels were subjected to various test environments like salt-spray, humidity, UV and mechanical tests like scratch and abrasion. The improvement in electrochemical performance and mechanical properties of the composite coatings were evaluated using various analytical techniques. FTIR technique was used to investigate the interaction between nano-ZnO particles and the polymer functionalities. Differential scanning calorimetry (DSC) was done to study the curing behavior of nano-composite coatings. SEM and AFM were used to investigate dispersion of nano-ZnO particles and the changes in the surface behavior of the coatings before and after exposure to the test environment. The result showed that, with increase in the concentration of nano-ZnO there was an improvement in the corrosion resistance, UV resistance and mechanical properties of the coatings indicating the positive effect of addition of nano-ZnO particles in the coatings. (C) 2008 Elsevier B.V. All rights reserved.