Abstract As corrosion inhibitors, a series of new amide derivatives of 13‐docosenoic acid was synthesized in yields of above 90% by reacting 13-docosenoic acid with primary and secondary aliphatic and aromatic amines. The inhibition efficiencies (%IEs) of these compounds at various concentrations for the suppression of corrosion of mild steel in 1.00 M HCl exposed for 96 h (4 days) at temperatures in the range 298–333 K were measured via gravimetric corrosion measurements. At 100 ppm, all compounds yielded satisfactory corrosion %IE in 1.00 M HCl; compounds 2 and 7 exhibited remarkable %IE of 70.0 and 74.7%, respectively. The results of gravimetric measurements further revealed that compound 7 performed excellently at 60 °C, with %IE = 96.8 at 500 ppm. Quantum chemical density functional theory (DFT) calculations helped predict that compound 7 should have more aromatic character, enabling it to serve as a donor-center for the empty d-orbital of the metal atoms, leading to higher corrosion IE. The adsorption of the inhibitor molecules on the surface of mild steel followed the Langmuir adsorption model, and the free energy of adsorption (ΔGads) value indicated that the inhibitors are adsorbed through a combined physisorption and chemisorption mechanism to provide effective surface coverage.

中文翻译：

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天然脂肪酸衍生的新型缓蚀剂的合成：用于石油和天然气工业的 13-二十二碳烯酸酰胺衍生物

摘要 作为缓蚀剂，13-二十二碳烯酸与脂肪族和芳香族伯胺和仲胺反应合成了一系列新的13-二十二碳烯酸酰胺衍生物，收率超过90%。这些化合物在不同浓度下抑制低碳钢在 298-333 K 温度范围内暴露 96 小时（4 天）的 1.00 M HCl 腐蚀的抑制效率 (%IEs) 是通过重量腐蚀测量来测量的。在 100 ppm 时，所有化合物在 1.00 M HCl 中产生令人满意的腐蚀 %IE；化合物 2 和 7 分别表现出显着的 70.0% 和 74.7% 的 %IE。重量测量结果进一步表明，化合物 7 在 60 °C 下表现出色，500 ppm 时的 %IE = 96.8。量子化学密度泛函理论 (DFT) 计算有助于预测化合物 7 应该具有更多的芳香性，使其能够作为金属原子空 d 轨道的供体中心，从而导致更高的腐蚀 IE。缓蚀剂分子在低碳钢表面的吸附遵循朗缪尔吸附模型，吸附自由能（ΔGads）值表明缓蚀剂通过物理吸附和化学吸附相结合的机制被吸附，提供有效的表面覆盖。