Effect of molecular structure of aniline–formaldehyde copolymers on corrosion inhibition of mild steel in hydrochloric acid solution

• Published in: Journal of hazardous materials Vol. 289; pp. 130 - 139
• Main Authors: Zhang, Yan, Nie, Mengyan, Wang, Xiutong, Zhu, Yukun, Shi, Fuhua, Yu, Jianqiang, Hou, Baorong
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 30.05.2015
• Subjects: Aniline Compounds - chemistry; Aniline–formaldehyde copolymer; Anticorrosion; Carbon steels; Copolymers; Corrosion; Corrosion inhibitors; Electrochemistry; Formaldehyde - chemistry; Hydrochloric acid; Hydrochloric Acid - chemistry; Inhibition; Inhibitor; Killed steels; Mild steel; Molecular structure; Polymers; Solutions; Steel - chemistry; Surface chemistry; Anticorrosion; Inhibitor; Mild steel; Aniline–formaldehyde copolymer; Molecular structure
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2015.02.036

•Copolymers synthesized with various ratios of aniline to formaldehyde in acid media.•Molecular structure of aniline–formaldehyde copolymers were studied spectrally.•Copolymers can act as effective corrosion inhibitors for mild steel in HCl solution.•Effect of aniline/formaldehyde ratio on copolymer corrosion inhibition is revealed. Aniline–formaldehyde copolymers with different molecular structures have been prepared and investigated for the purpose of corrosion control of mild steel in hydrochloric acid. The copolymers were synthesized by a condensation polymerization process with different ratios of aniline to formaldehyde in acidic precursor solutions. The corrosion inhibition efficiency of as-synthesized copolymers for Q235 mild steel was investigated in 1.0molL−1 hydrochloric acid solution by weight loss measurement, potentiodynamic polarization, and electrochemical impedance spectroscopy, respectively. All the results demonstrate that as-prepared aniline–formaldehyde copolymers are efficient mixed-type corrosion inhibitors for mild steels in hydrochloric acid. The corrosion inhibition mechanism is discussed in terms of the role of molecular structure on adsorption of the copolymers onto the steel surface in acid solution.