Electrochemical properties of aluminum tripolyphosphate modified chemically bonded phosphate ceramic anticorrosion coating. (10th August 2020)

• Record Type: Journal Article
• Authors: Ding, Zhu; Li, Yu-Yu; Xu, Mu-Rui; Hong, Xin; Hong, Shu-Xian; Dong, Biqin
• Is Part Of: Construction & building materials. Volume 251(2020)
• Publication Date: 2020-08-10
• Subjects: Inorganic coatings -- Chemically bonded phosphate ceramic binder -- Aluminum tripolyphosphate -- Corrosion -- Electrochemical property; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2020.118874
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: Chemically bonded phosphate with aluminum tripolyphosphate（ATP）as pigment is designed for anti-corrosion coating. The coating has better electrochemical protection performance, smaller porosity and water absorption. The coating combined by chemically bonded phosphate and ATP pigment forms a passivation layer on steel surface. Abstract: An inorganic coating, combining chemically bonded phosphate ceramic (CBPC) binder and aluminum tripolyphosphate (ATP) pigment, was designed and prepared for anti-corrosion treatment of steel. An electrochemical method was proposed to characterize and evaluate the corrosive behavior of the coating, and the influence of ATP contents associated with XRD and SEM/EDS techniques. The experimental results showed that the addition of the ATP pigment increased the corrosion potential and reduced the corrosion current density, porosity, and water absorption of a coating. Moreover, the polarization resistance (Rp ) values were more than twice those of CBPC binder when the ATP was added. The best anti-corrosion profile of the coating was observed when the content of ATP pigment was 15%, which exhibited the least negative corrosion potential (Ecorr ) and Rp and smallest corrosion current (Icorr ). SEM-EDS results indicate that ATP exhibited more metal ion chelating power than the CBPC binder itself, which shows the better interfacial binding ability. The said coating cannot only provide excellent physical protection but form passivation layer on the surface of a steel substrate to protect it and prevent further corrosion.