This paper aims to prepare a residual rust epoxy coating by adding different quantities of phytic acid (PA) on the surface of the rusty steel and investigate the corrosion protection of PA and its action mechanisms.
A residual rust epoxy coating by adding different quantities of PA was prepared on the surface of the rusty steel. The influence of PA on the corrosion resistance of epoxy-coated rusty steel was investigated by means of electrochemical impedance spectroscopy and adhesion testing.
Results indicated that PA can substantially improve the corrosion resistance of epoxy-coated rusty steel. This improvement is due to the reaction of PA with residual rust and generation of new compounds with protection properties and increased adhesive strength effects on the coating/metal interface. The coating showed better protection performance when 2 per cent PA was added.
Considering the structure of the active groups, PA has strong chelating capability with many metal ions and can form stable complex compounds on the surface of a metal substrate, thereby improving corrosion resistance. In recent years, PA has been reported to be useful in the conversion of coatings or as green corrosion inhibitor. To the best of the authors’ knowledge, few studies have reported the use of PA as a rust converter or residual rust coating. The present work aims to improve the corrosion resistance of residual rust epoxy coating by adding PA.
The authors wish to acknowledge the financial supports of the Research Foundation for the Introduction of Talent of Sichuan University of Science and Engineering, China (Grant No. 2016RCL13), the Foundation of Material Corrosion and Protection Key Laboratory of Sichuan Province, China (No. 2017CL10), Key Projects of Science and Technology Plan of Zigong, China (Grant No. 2017XC09), the National Natural Science Foundation of China–Civil Aviation Joint Research Funds (Grant No. U1633118).
Zhang, Y., Cui, X.-J., Shao, Y., Wang, Y., Meng, G., Lin, X.-Z., Zhong, D. and Wang, D. (2019), "Role of phytic acid in the corrosion protection of epoxy-coated rusty steel", Anti-Corrosion Methods and Materials, Vol. 66 No. 2, pp. 188-194. https://doi.org/10.1108/ACMM-07-2018-1973
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