Abstract

The article investigates the role of carbon nanomaterials (CNMs), surface-oxidized carbon nanotubes (CNTs) and few-layer graphene fragments (FGFs), as well as FGFs hetero-doped with N and P atoms, as anticorrosive additives in industrial paints based on polyvinyl chloride. All CNMs were characterized by thermogravimetry, transmission electron microscopy, low-temperature nitrogen adsorption, and X-ray photoelectron spectroscopy. Corrosion resistance was determined using electrochemical tests and impedance spectroscopy. The surface and internal 3D structure of steel and coated steel were visualized using laser confocal microscopy and computed tomography. Coatings containing polyvinyl chloride with 0.05 wt% oxidized CNTs or FGFs show the highest electrochemical resistance and the best anticorrosive properties. The corrosion rate for coatings containing CNMs decreases by an average of 5–7 times compared to uncoated steel. It is shown that the improvement in anticorrosive characteristics is determined by the texture parameters and the composition of CNMs. The pores in CNMs act as a reservoir for the electrolyte and increase the corrosion rate. Oxygen-containing surface groups prevent corrosion by increasing the resistance of the materials.

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