Development of volatile corrosion inhibitor (VCI) with potential for use in packaging industry

In this study, the effect of a volatile corrosion inhibitor (VCI) mixture containing boron-amine complex, carboxylic acid, and ester groups on the corrosion behavior of St37 carbon steel in a 3.5% NaCl solution was evaluated. The efficacy of the VCI in providing corrosion protection was determined through the implementation of electrochemical impedance spectroscopy (EIS) and Tafel polarization (TP) tests. Furthermore, VCI tests that were compliant with the TL-8135-0043 standard, a prevalent industry standard, were performed to validate the effectiveness of the inhibitor. In addition, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDAX), and atomic force microscopy (AFM) were utilized to examine the protective coating formed by the inhibitor on the steel surface. The findings of the Electrochemical Impedance Spectroscopy (EIS) analysis indicated a substantial enhancement in corrosion resistance that was concomitant with elevated Vanadium-based Corrosion Inhibitors (VCI) concentrations. A thorough analysis of the Nyquist plots indicated that VCI offered 71.24% protection. The characterization results demonstrated that the inhibitor adheres to the surface, thereby impeding charge transfer and decreasing the corrosion rate. The results of the TP tests demonstrated that VCI functions as an anodic-type inhibitor, primarily inhibiting anodic dissolution. The VCI test was conducted in accordance with the standards delineated in TL-8135-0043, and no indications of corrosion were observed on metal samples covered with VCI-impregnated paper for a period of up to 30 days. The use of SEM-EDAX and AFM evaluations revealed that the inhibitor adheres to the metal surface, forming a protective layer.