Synthesis and characterization of protective silica reinforced hybrid poly(vinylpyrrolidone)/acrylate/silane nanocomposite coatings

Abstract

In this work, the protective performance of a new silica doped coating on steel has been investigated. Silica nanoparticles (SiO₂NPs) were incorporated within a hybrid polymer coating synthesized via controlled silanization and free-radical polymerization using poly(vinylpyrrolidone), acrylic and silane precursors. Variants of the coating were prepared from different concentrations of SiO₂NPs and characterized before applying them on steel substrates to prevent corrosion during treatment in chloride-enriched media. These new SiO₂NP-modified hybrid nanocomposite coatings have demonstrated significant resistance against steel corrosion; corrosion resistance increased with the SiO₂NP content. The SiO₂NPs acted as coating fillers, delaying underfilm steel corrosion. The neat polymer coating without SiO₂NPs demonstrated greater surface damage and induced pitting upon chloride treatment. Without nano-silica reinforcement, the coating network is porous with delaminated and hydrophilic surfaces. Apart from increasing the gross contact angle of the coating surfaces, the presence of SiO₂NPs also contributed to toughened mechanical strength.