Using nanoemeraldine salt-polyaniline for preparation of a new anticorrosive water-based epoxy coating

In this study the anticorrosion performance of a two components water-based epoxy coating system is improved by using the nanopolyaniline (nanoPAni) particles. The purchased nanopolyaniline which was dispersed in water was mixed mechanically with the water-based polyamidoamine hardener of the epoxy system using ultrasonic homogenizer. Average particle size of the polyaniline in hardener was determined using dynamic light scattering technique (DLS). Results revealed that the particles were in the range of 50–57 nm. After combining the prepared sample with the DGEBA epoxy resin, finished coating was applied on steel substrates. Anticorrosion performance and adhesion properties of coating which contained nanoPAni were compared to the model water-based epoxy coating with the help of salt spray and adhesion tests. Results showed that anticorrosive performance of the model water-based epoxy system improved dramatically by adding only 0.02 wt.% nanoPAni. However in contrast to model coating, adherence of PAni-epoxy coating to steel plates was remained constant after their exposure to the corrosive media.