Organic corrosion inhibitors from natural plant resources have received extensive attention in recent years. Herein, an eco‐friendly corrosion inhibitor lignin–(2,3‐epoxypropyl)trimethyl ammonium chloride (EPTAC) was successfully prepared by grafting EPTAC to kraft lignin. The inhibiting efficiency and its inhibition mechanism were investigated using electrochemical methods, adsorption thermodynamics analysis, and molecular dynamic simulation. The results showed that the lignin–EPTAC molecules formed a protective film on iron surface, resulting in an excellent inhibition efficiency of 97.80% at 100 mg/L concentration. The average surface roughness of steel samples was reduced to 26.6 nm from the original 99.3 nm. The adsorption of lignin–EPTAC molecules on the steel surface follows Langmuir adsorption isotherm model and was a physical–chemical process as well as an exothermic process of entropy reduction. This adsorption of lignin–EPTAC was a conjugated system dominated by benzene ring of lignin–EPTAC to form a chemical bond on the steel surface by conjugation, besides a positive interaction between the metal surface and the positively charged N ions in the head group of lignin–EPTAC.

中文翻译：

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环保型缓蚀剂木质素衍生物的构建，在盐酸溶液中具有优异的耐腐蚀性能

近年来，来自天然植物资源的有机腐蚀抑制剂已受到广泛关注。在这里，通过将EPTAC接枝到硫酸盐木质素上，成功制备了一种环保型缓蚀剂木质素-（2,3-环氧丙基）三甲基氯化铵（EPTAC）。利用电化学方法，吸附热力学分析和分子动力学模拟研究了其抑制效率及其抑制机理。结果表明，木质素-EPTAC分子在铁表面形成了一层保护膜，在100 mg / L的浓度下，抑制效率高达97.80％。钢样品的平均表面粗糙度从最初的99.3 nm降低到26.6 nm。木质素-EPTAC分子在钢表面的吸附遵循Langmuir吸附等温线模型，是物理化学过程以及熵降低的放热过程。木质素-EPTAC的这种吸附是一个共轭体系，木质素-EPTAC的苯环占主导地位，通过共轭作用在钢表面形成化学键，此外金属表面与木质素头基中带正电的N离子之间存在正相互作用–EPTAC。