Epoxy resins and their nanocomposites as anticorrosive materials

Epoxy resins and their nanocomposites are efficient coating systems. The coatings are obtained using polyols, polyamines, polyamides, etc. They are extensively used as anticorrosive materials for different metals and alloys. Due to the polymeric nature, the epoxy resins possess high surface area that offers them high anticorrosive activity. Several epoxy resins have been used as corrosion inhibitors in aqueous, as well as in coating phase. Instead of their polymeric nature possess high solubility in the polar electrolytes, which is attributed to their high surface functionalities. Presence of numerous peripheral functional groups such as amino (-NH₂), hydroxyl (-OH), amide (-CONH₂), and so on enhances their solubility in such electrolytes. Several experimental studies such as weight loss, electrochemical, scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDS), (EDS) and theoretical measurements including density functional theory (DFT) and molecular dynamics (MD) simulation are extensively used for evaluation of anticorrosive effect of the epoxy resins and their nanocomposites. Both experimentally and computationally, it was seen that nanocomposites showed better anticorrosive effect than that of polymeric, which is attributed due to filing out the surface micropores of the coating structures through which corrosive species can penetrate and accelerates corrosion. Literature studies showed that epoxy resins and their nanocomposites are used as corrosion inhibitors, especially in NaCl and acidic media.