Determining the Effect of 1, 3, 5-trimethyl-2, 6-diphenyl Piperidin-4-one Oxime on the Electrochemical Behaviour of Mild Steel in HCl Medium

Abstract

Weight loss experiments, electrochemical methods, and SEM studies in 1M hydrochloric acid (HCl) medium against mild steel (MS) were used to evaluate the corrosion inhibiting ability of a synthetic heterocyclic compound, namely 1, 3, 5-trimethyl-2, 6-diphenyl piperidin-4-one oxime (TPO).  The weight loss trials were carried out at three distinct temperatures: 30°C, 40°C, and 50°C for two hours at varied concentrations (0, 25, 50, 100, 200, and 300 ppm).The study discovered that increasing TPO concentration had a positive link with inhibition efficiency while raising temperature had a negative correlation.TPO physically adsorbs on mild steel surfaces, following Temkin’s isotherm. Tafel plot was used to determine electrochemical parameters such as corrosion potential (Ecorr), corrosion current (icorr), and Tafel slopes (ba & bc). TPO significantly reduces corrosion current and acts as a mixed mode inhibitor, according to the findings. The charge transfer resistance (Rct) and double layer capacitance (Cdl) were calculated using the AC impedance measurement determined by the Nyquist plot, whose results complimented each other. TPO's ability to form films in HCl medium was revealed by SEM studies. The values of Rct increase with increase of TPO concentration showed TPO as good inhibitor.