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