Aminoantipyrine derivatives as a novel eco-friendly corrosion inhibitors for P110 steel in simulating acidizing environment: Experimental and computational studies

The present paper deals with the synthesis and corrosion inhibition evaluation of aminoantipyrine (AAPs) derivatives on P110 steel in 15% hydrochloric acid solution using standard techniques such as weight loss, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP). The predicted toxicity (LD₅₀) values are 1482 mg/kg (AAP-1) and 1380 mg/kg (AAP-2). AAPs are effective corrosion inhibitors giving inhibition efficiency of 95% (AAP-1) at only 400 mg/L concentration. Adsorption of AAPs on the P110 steel surface involves both physical and chemical interactions. The EIS results suggest an increased value of charge transfer resistance with increasing AAPs concentration. PDP result reveals that AAP's are mixed type inhibitors with anodic predominance. SEM, AFM, contact angle and XPS spectra, confirmed the presence of adsorbed inhibitor film. DFT study confirms the participation of both neutral and protonated forms in the corrosion inhibition process. The interaction of AAPs with P110 steel was analyzed by MD simulation that includes the calculation of adsorption energy, RDF, diffusion coefficients, and fractional free volume.