Abstract:

Cationic polymerizable imdazolium ionic liquid-acrylamide copolymers as the corrosion inhibitors were successfully prepared by copolymerization of hydrophilic polymerizable ionic liquid, 1-methyl-3-[2-[(1-oxo-2-propenyl)oxy]ethyl]imdazoliumtetrafluoroborate(ACIMBF₄), with acrylamide via inverse microemulsion polymerization. Various impact factors on the inhibition of carbon steel corrosion by hydrochloric acid including the cationic degree, the relative molecular mass of the copolymer, the concentration of copolymer solution and the absorption time were investigated simultaneously, and the corrosion mitigation mechanism was also discussed preliminary. The corrosion inhibition efficiency of cationic ionic liquid-acrylamide copolymers can reach higher than 90% by forming a protective adsorption film on the carbon steel. The corrosion inhibition ability of cationic copolymer depends on not only its cationic degree but also its relative molecular mass. Moreover, the corrosion inhibition efficiency increases with the increase of the concentration of cationic poly(ionic liquid) copolymer, and then decreases when the concentration of copolymer solution is too high. Furthermore, with the extension of the adsorption time, the corrosion rate of carbon steel is reduced gradually, and remains constant after approximately 40 h, namely the absorbing capacity of inhibitor on the carbon steel reaches the maximum.

Key words: cationic polymerizable imdazolium ionic liquid, ionic liquid-acrylamide copolymer, cationic degree, corrosion inhibitor, corrosion mitigation mechanism