Analysis of synergistic effect of nanozinc/nanoclay additives on the corrosion performance of zinc-rich polyurethane nanocomposite coatings

The aim of this study was to analyze the synergistic effect of clay and zinc nanopigments. Therefore different percentages of Montmorillonite clay nanolayers were added to zinc-rich polyurethane nanocomposites. Ultrasonication process was used to prepare polyurethane/nanozinc/nanoclay nanocomposites. Then coatings were applied on steel panels with composition of 10 wt% nanozinc and 0.5, 1, 1.5, and 2 wt% nanoclay. TEM and XRD were used to analyze the structural characteristics of the nanocomposites. The results of the structure analysis revealed the size of nanomaterials and confirmed the appropriate dispersion in polymer matrix. The anticorrosive properties of the nanocomposites were investigated using salt fog test and electrochemical impedance spectroscopy (EIS). The results of EIS showed that addition of clay nanolayers improves the corrosion resistance of coatings and the best corrosion performance obtained for the nanocomposite sample with 2 wt% nanoclay. Also, according to the results of the salt spray test, the sample with 2 wt% nanoclay showed the least H2O penetration and exfoliation adjacent to the scratches. POLYM. COMPOS., 2012. (c) 2012 Society of Plastics Engineers