Microwave-assisted synthesis of organic corrosion inhibitor based imidazoline-stearic

Abstract

Corrosion often occurs in oil and gas industries’ pipelines indicated by a decrease in quality which is harmful to the industries and environment. To slow down the corrosion rate, a corrosion inhibitor is needed. Organic corrosion inhibitors are more widely used than inorganic ones due to its effectiveness and non-toxic. One of the most widely used organic corrosion inhibitors is imidazolines. In this study, imidazoline-stearic was successfully synthesized from triethylenetetramine (TETA) with various purity grade of stearic acid (SA) using 800 W microwave irradiation at 200 °C for 9 min. The obtained products then were separated by a solvent extraction method and identified using thin layer chromatography (TLC). Moreover, the products had also been characterized using FTIR and UV-Vis spectral data. The ability to inhibit corrosion on carbon steel in 1 % NaCl solution was evaluated to obtain inhibition efficiency (%IE). %IE at 500 ppm of imidazoline-stearic from SA pro analysis, technical, and commercial sample were 84.43 %, 75.42 %, and 84.41 %, respectively. Imidazoline-stearic from SA pro analysis revealed a similar corrosion inhibition activity compared with the commercial. Hence, imidazoline-stearic from SA technical grade demonstrated a promising corrosion inhibitor by using economical fatty acid.