Author(s)

Dongqiu Yang¹, Xiaojun Feng¹, Ning Yan¹, Yanqun Wang¹, Lilin Lu², Ping Mei¹, Wu Chen¹, Lu Lai^1*

¹College of Chemistry and Environmental Engineering, Yangtze University, Jingzhou, China.
²College of Chemistry and Chemical Engineering, Wuhan University of Science and Technology, Wuhan, China.

Three benzoxazole corrosion inhibitors, namely 2-(benzo [d]oxazol-2-yl)phenol (BOP), 6-(benzo [d]oxazol-2-yl)pyridin-2-ol (BOPO), and 2-(quinolin-2-yl) benzo [d]oxazole (QBO), were synthesized. Moreover, their corrosion inhibition performance for N80 steel in 1 M HCl solution at 303 K was measured by the electrochemical measurements and surface analysis studies. The results show that the inhibition efficiency of all corrosion inhibitors increases with the increase of concentration. At the same concentration, the order of inhibition efficiency is BOP < BOPO < QBO. Moreover, the studied inhibitors act as mixed-type inhibitors, and the adsorption of all inhibitors on N80 steel followed the Langmuir adsorption isotherm. Further, we have examined the effect of iodide ions on inhibition efficiency. The results show that BOP and KI are synergistic, BOPO and QBO are competitive adsorptions with KI. The quantum chemical parameters such as highest occupied molecular orbital, lowest unoccupied molecular orbital energy levels, and energy gap were calculated by the density functional theory (DTF). The relations between the inhibition efficiency and some quantum parameters have been discussed. The protective effect of the three inhibitors followed the sequence of BOP < BOPO < QBO. The results obtained from quantum chemicals and electrochemical were in reasonable agreement.

N80 Steel, Benzoxazole Derivatives, Corrosion Inhibition, Electrochemical Measurements, DFT

Yang, D. , Feng, X. , Yan, N. , Wang, Y. , Lu, L. , Mei, P. , Chen, W. and Lai, L. (2022) Corrosion Inhibition Studies of Benzoxazole Derivates for N80 Steel in 1 M HCl Solution: Synthesis, Experimental, and DTF Studies. Open Journal of Yangtze Oil and Gas, 7, 101-123. doi: 10.4236/ojogas.2022.72007.