Synthesis and investigation of two new compounds (2-(methoxymethyl)−1- phenyl-2-propen-1-one and 2-(methoxymethyl)−1-(4-methoxyphenyl) - 2-Propen-1-one) as corrosion inhibitors for mild steel in acidic solutions at elevated temperature.

Abstract

This study evaluated the performance of two newly synthesized organic corrosion inhibitors using the gravimetric weight loss method in hydrochloric acid (HCl), methanesulphonic acid (MSA), and a combination of HCl and MSA in the presence of different corrosion inhibitor (CI) concentrations at temperatures of 30 °C to 90 °C. Potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) studies were carried out for an in-depth study of corrosion mechanisms. Following the weight loss study, the percentage inhibition efficacies of C1 and C2 at 300 ppm concentrations were found to be ≈ 100% at 30 °C, 40 °C and 60 °C in 15 wt% HCl, 10 wt% MSA, and a combination of both acids (15 wt% HCl and 10 wt% MSA). The performances of C1 and C2 deteriorated slightly when tested in 10 wt% MSA at 90 °C. The synthesized CIs still showed a very high inhibition efficiency in the presence of 15 wt% HCl and a mixture of acids (HCl and MSA) at 90 °C. PDP studies indicated that both C1 and C2 act as anodic inhibitors. The inhibition efficiencies obtained from the PDP and EIS studies agreed with the weight loss study. The high value of Kads and the negative ∆Gads value suggests that C1 and C2 corrosion inhibitors have a strong and spontaneous tendency to chemisorb onto the mild steel surface. SEM-EDX studies proved the formation of a uniform, protective corrosion inhibitor film on the metal surface. Both C1 and C2 have been proven suitable for high-temperature corrosion applications.