Epoxy-Montmorillonite Nanocomposites:The Influence of Hardener Reactivity on Morphology and Corrosion Resistance Properties

Epoxy–clay nanocomposites were prepared by applying high- intensity ultrasound during the synthesis of clay – epoxy nanocomposites by two kinds of amineous curing agent, cycloaliphatic and amidoamine. Exfoliation and intercalation of nanoclay have a significant effect in improvement of physical and chemical epoxy coatings properties. The choice and condition of curing agent controls the contribution of nanoclay of these coatings.In this article, X-ray diffraction (XRD), Optical microscopy and Scanning Elecron Spectroscopy(SEM) analyses were carried out. The results of XRD showed that the distances between the silicate layer were increased from 18.02 A° to 38.5 and 41.6 A°, in two coating systems. The results of Scanning Elecron Spectroscopy(SEM) showed the nanoclay particles in the polyamidoamine coating are composed of 3% of nano with flake structure that increase the direction of the ions in the time of getting the metal surface. The result of optical microscopy also shows the appropriateness of the ultrasound method in preparing nanocomposits. By using the results of Electrochemical Impedance(EIS)and Salt spray, the corrosion resistance of nanocomposites were obtained. From electrochemical impedance spectroscopy, it was observed that nanocomposite coating epoxy-polyamidoamine, with the formulation consisting of 3% nanoclay had the excellent corrosion resistance in comparison to pure epoxy coating.