Evaluation of the anticorrosion performance of Tamsulosin as corrosion inhibitor for pipeline steel in acidic environment: experimental and theoretical study

Abstract

The inhibition performance of expired Tamsulosin (TAM) was studied on St52 pipeline steel in 1 M HCl by gravimetric, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) spectroscopic analysis. It was seen that the presence of the studied expired drug decreased the corrosion rate of the pipeline steel. TAM’s efficiency as an inhibitor increased as its concentration increased but decrease with temperature rise. The expired drug showed maximal inhibition efficiency of 98.1% from weight loss measurement at 2.0 × 10−3 M TAM concentration and 303 K. PDP results showed that TAM acted as a mixed-type inhibitor. The adsorption study revealed that Langmuir isotherms gave the best fit. The surface morphological study revealed that TAM formed an adsorbed protective layer on the St52 steel surface in the acid medium. The theoretical study performed using the density functional theory (DFT) allowed correlation with an experimental study.