Development of Waterborne Heavy-Duty Anticorrosive Coatings with Modified Nanoscale Titania

The steel structures of coastal engineering in the moist tropics and subtropics are always under a C5/CX level corrosion environment with high temperature, high humidity, and high salt fog. Anticorrosive waterborne coatings with high weatherability and reliability are urgently to be developed. In this work, one kind of waterborne heavy-duty anticorrosive coatings, with the advantages of excellent corrosion resistance, self-repairing ability, self-cleaning ability, and high film compactness, was successfully achieved through modifying the side chains on the surface morphologies of the spherical nanoscale titania. The micromorphology and structure of the coating were characterized by a scanning electron microscope (SEM), transmission electron microscope (TEM), and atomic force microscope (AFM). The anticorrosion characteristics and forming mechanism of the modified nanoscale titania coating were analyzed. The salt spray tests showed that the neutral salt spray resistance time of the modified nanoscale titania coating was 1440 h. Its durability reached the H level and met the design requirements for 15 years of anticorrosion lifetime. The modified nanoscale titania coatings had been large-scale commercially applied at some typical steel structures under an extreme harsh corrosion environment in one coastal thermal power plant. The results showed that no rusting, peeling, or crack phenomena were observed after 3 years of service under different harsh coastal corrosion conditions.