Guanidine-Containing Alkyl-Substituted Oligomer as a Metal Corrosion Inhibitor.

Guanidinium-containing oligomer based on aliphatic oligoepoxide is a newly synthesized substance with known bactericidal action, which is prospective as a microbial corrosion inhibitor. The oligomeric alkyl-substituted guanidine bromide is synthesized and its anticorrosive properties for steel in the presence of corrosive aggressive sulfate-reducing bacteria (SRB) are studied. The effectiveness of the new compound is compared with previously studied inhibitors DPH (quarter ammonium compound based on N-decylpyridinium chloride) (National Technical University, Kyiv, Ukraine) and Armohib CI-28 based on Diamine Ethoxylate (Akzonobel, Holland). The guanidine oligomer has biocidal properties. It significantly inhibits the growth of bacteria, and after the end of its exposure period only dozens of bacteria were found in the environment. The steel corrosion rate in the presence of SRB without inhibitors equals 0.15–0.35 mg/(cm2·h). The addition of DPH reduces the corrosion rate of steel to 0.032–0.047 mg/(cm2·h) (in 6.5–10.6 times). The addition of Armohib CI-28 reduces the corrosion rate to 0.027–0.039 mg/cm2·h (in 4.2–12.7 times). After the addition of the oligomer to the culture medium reduces with bacteria the corrosion rate decreases to 0.075–0.079 mg/(cm2·h) (in 2.5–2.7 times). According to the results of steel samples mass loss, the degree of the metal protection from microbial corrosion in the presence of guanidine oligomer is 60.15–63.17%. So, the guanidine-containing oligomer based on aliphatic oligoepoxide has biocidal and ant-corrosion properties and is promising for combating microbial induced corrosion. [ABSTRACT FROM AUTHOR]