Posted August 16, 2017 by Rino Rakhmata Mukti, Dr. rer.nat in Riset

Performance of oligomer 4-vinylpiperidine as a carbon dioxide corrosion inhibitor of mild steel

Journal of Materials and Environmental Science
Volume 8, Issue 7, 2017, Pages 2381-2390

Performance of oligomer 4-vinylpiperidine as a carbon dioxide corrosion inhibitor of mild steel

Oligomer of 4-vinylpiperidine, O(4-VPP), synthesized by hydrogenation of oligomer 4-vinylpyridine, O(4-VP), was tested as a corrosion inhibitor to protect mild steel in brine solution saturated by carbon dioxide (CO2). Weight loss (wheel test), electrochemical impedance spectroscopy (EIS), and linear polarization (LP) measurements were used to determine the corrosion rates and the efficacies of the synthesized O(4-VPP). Weight loss experiments were carried out at temperature of 50 °C, in two different conditions, i.e without and with kerosene addition, while the other two techniques were applied only in brine solution without kerosene. Weight loss experiments demonstrated that the % protections of the synthesized inhibitor with the concentration of 10 mg L-1 are 62.7±9.9 % in the absence of kerosene, and 58.1±1.6 % in the presence of kerosene. Based on the significant test, % protections of O(4-VPP) in brine solution with and without kerosene are not significantly different. EIS experiments were carried out at fixed temperature of 70 °C, and the results indicate that addition of 1 mg L-1 of O(4-VPP) to brine solution led to increased charge transfer (Rct) from 21.8 Ω cm2 to 49.9 Ω cm2, and with addition of 2 mg L-1 led to increased Rct up to 90.9 Ω cm2, confirming the ability of the inhibitor to significantly decrease the corrosion rate of the mild steel investigated. To assess the effect of temperatures, the LP experiments were run at different temperatures of 30, 50, and 70 ° C in the concentration range of inhibitor from 0 to 20 mg L-1. The results demonstrated that the higher the temperature and concentration, the higher the protection exhibited by the inhibitor suggesting that the inhibitor of O(4-VPP) was adsorbed onto surface of the mild steel through chemisorption supported by the adsorption thermodynamic parameters. © 2017, University of Mohammed Premier Oujda Morocco.