Synthesis and Corrosion Inhibition Performance of Mannich Bases on Mild Steel in Lactic Acid Media

Abstract

Heterocyclic Mannich bases, N -(3-oxo-3-phenylpro-pyl)thiazol-2-aminium chloride (DTZA) and N -(3-oxo-3-phenylpropyl)-1 H -pyrazol-3-aminium chloride (DPZA), were developed for the corrosion inhibition of N80 steel in a 15 wt % lactic acid solution. Weight loss measurements, electrochemical techniques, surface characterization, and theoretical calculations were combined to investigate their anticorrosion performance and mechanism. The results showed that DTZA exhibited a satisfactory inhibitor efficiency of 97.56% with a dosage of 0.15% at 363 K, while DPZA achieved only 58.3% under the same conditions. Adsorptions of both inhibitors on the metal surface followed the Langmuir model with physical and chemical adsorptions. Based on X-ray photoelectronic spectroscopy (XPS) analysis, DFT calculations, and molecular dynamics (MD) simulations, stronger interactions between DTZA and iron than those in the case of DPZA were revealed, leading to the formation of a compact protective film on the metal surface, which is attributed to the presence of a thiazole ring in the DTZA chemical structure.

Exploring corrosion protection for mild steel in HCl solution: An experimental and theoretical analysis of an antipyrine derivative as an anticorrosion agent

“…Since the inhibitor adsorbed onto the metal surface, they blocked the majority of electroactive sites, which led to the remaining corrosion sites being a measure of the corrosion rate. [ 39 ] Assuming that only free sites contributed to corrosion, and that blocked sites made a negligible contribution, the IE values could be related to the surface coverage ($$\theta $$). This relation is given by the following equation, which is a commonly used expression.…”

Multi-method evaluation of a 2-(1,3,4-thiadiazole-2-yl)pyrrolidine corrosion inhibitor for mild steel in HCl: combining gravimetric, electrochemical, and DFT approaches

“…This indicates that it has a good versatility and adaptability, which is essential for industrial applications. Moreover, 2-TP has a low toxicity and environmental impact, making it a safer and more sustainable option for industrial applications compared to other nitrogen-based inhibitors 42 . To the best of our knowledge, there have been no reports of corrosion inhibitors suitable for HCl solutions.…”

Synthesis of alkynyl alcohol derivatives and its corrosion inhibition on N80 steel in 5 M HCl

“…Consequently, in the last few decades, there have been many studies focusing on synthetic organic inhibitors for anti-corrosion in acidic solutions. [7][8][9] The most widely used organic inhibitors take the isolated pair electrons of O, N, S, P and π electrons in aromatic rings as their main adsorption centres, such as Mannich bases, 10,11 Schiff bases 12,13 and imidazoline derivatives. 14,15 In addition, a large number of studies have indicated that alkyl alcohol derivatives [16][17][18] and alkyl pyridine [19][20][21] have good corrosion inhibition performance on metals in acidic media.…”