Effect on the Surface Anticorrosion and Corrosion Protection Mechanism of Integrated Rust Conversion Coating for Enhanced Corrosion Protection

Pengfei Yu; Yun Lei; Zhaolin Luan; Yonggang Zhao; Haoping Peng

doi:10.1021/acsomega.2c00172

Effect on the Surface Anticorrosion and Corrosion Protection Mechanism of Integrated Rust Conversion Coating for Enhanced Corrosion Protection

ACS Omega. 2022 Mar 1;7(10):8995-9003. doi: 10.1021/acsomega.2c00172. eCollection 2022 Mar 15.

Authors

Pengfei Yu¹, Yun Lei¹, Zhaolin Luan^{1

2}, Yonggang Zhao^{1

3}, Haoping Peng^{1

4

5}

Affiliations

¹ Jiangsu Key Laboratory of Oil and Gas Storage & Transportation Technology, Changzhou University, Jiangsu 213164, China.
² CNOOC Changzhou Paint and Coatings Industry Research Institute, Changzhou 213000, Jiangsu, China.
³ Corrosion and Protection Center, Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083, China.
⁴ Jiangsu Key Laboratory of Material Surface Science and Technology, Changzhou University, Jiangsu 213164, China.
⁵ Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Changzhou University, Jiangsu 213164, China.

Abstract

Here, a series of integrated rust conversion agents/coatings were synthesized by esterification reaction of 3,4,5-trihydroxybenzoic acid (GA) and triethanolamine (TE). The structural features, rust conversion ability, and corrosion resistance of the synthesized rust conversion agents/coatings were analyzed using the Fourier transform infrared tests, scanning electron microscopy tests, X-ray diffraction tests, and electrochemical measurements. It was found that when the mass ratio of TE and GA was 2:1, the synthesized rust conversion agent/coating has best rust conversion ability and anti-corrosion performance (i.e., corrosion current density 7.480 × 10^-7 A/cm²). In addition, different from the traditional coatings, the integrated rust conversion coating developed in this study combines the primer and topcoat of traditional coatings into one, which can significantly increase the on-site construction efficiency. Furthermore, a new rust conversion mechanism for the optimized rust conversion agent/coating was proposed. The phenolic hydroxyl functional groups in the rust conversion agent can well chelate with Fe²⁺/Fe³⁺ in the original rust layer and then form macromolecular compounds and dense chelating films inside the coating, which tightly wraps rust and also prevents the penetration and diffusion of corrosive medium, making them lose the opportunity to interact with each other.