Assessing Bifunctional Benzyldodecyldimethylammonium Bromide in Mitigating Abiotic and Biotic Corrosion Using a New Test Kit

Abstract Benzyldodecyldimethylammonium bromide (BDA-C12) is a corrosion inhibitor which forms a protective film layer on metal surfaces. It can also function as a biocide. This work assessed the performances of BDA-C12 in mitigating abiotic corrosion caused by CO2 and microbiologically influenced corrosion (MIC) caused by highly corrosive sulfate reducing bacterium (SRB) Desulfovibrio ferrophilus IS5 against X65 carbon steel. The initial efficacy screening was performed conveniently using a 10 mL disposable test kit with two solid-state electrodes for electrochemical measurements. In the corrosion prevention tests in which BDA-C12 was added into both the abiotic and biotic systems upon coupon immersions, 200 ppm (w/w) BDA-C12 was found to reduce the abiotic corrosion considerably (by 85%), and it successfully prevented the SRB biofilm formation, reflected by the linear polarization resistance (LPR) and potentiodynamic polarization scans. The loose coupon weight loss tests in 125 mL anaerobic vials containing 50 mL enriched artificial seawater confirmed the 10 mL test kit data. In the injection tests, the 500 ppm BDA-C12 injections in the abiotic and biotic systems achieved 14% and 34% polarization resistance (Rp) increases (corrosion rate decreases) from LPR measurements, respectively. Sessile cell counts and biofilm images supported the MIC inhibition results.