This study explores conducting polymers with side chains containing long, branched alkyl groups as candidates for corrosion suppression coatings. These polymers, containing carbazole, phenothiazine, and phenoxazine cores, may be considered as analogues to polyaniline, which is often employed in corrosion control applications. The polymers are prepared from the corresponding dibrominated carbazole, phenothiazine, and phenoxazine monomers with 2,5-dimethyl-1,4-phenylenediamine by the Buchwald–Hartwig coupling reaction. The effectiveness of these coatings for corrosion suppression was tested by potentiodynamic polarization studies and electrochemical impedance spectroscopy. The morphology of the coatings was characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Corrosion testing of coated AISI 4130 steels in 3.5 wt % NaCl showed that the phenothiazine- and carbazole-containing polymers display excellent corrosion resistance. The protection efficiency (PE) of 95.9% for phenothiazine outperformed the other polymers, including polyaniline coating. SEM images indicate that the polymers are still uniformly coated with stable morphology after 24 h of exposure to corrosive media. These results suggest that phenothiazine- and carbazole-based PANI analogues may be candidates for protective organic coatings in transportation, aviation, marine, and oil and gas industrial applications.

中文翻译：

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聚（杂环二苯胺）腐蚀防护涂料：聚苯胺类似物

本研究探索侧链含有长支链烷基的导电聚合物作为腐蚀抑制涂层的候选材料。这些含有咔唑、吩噻嗪和吩恶嗪核的聚合物可被视为聚苯胺的类似物，聚苯胺经常用于腐蚀控制应用。该聚合物由相应的二溴化咔唑、吩噻嗪和吩恶嗪单体与 2,5-二甲基-1,4-苯二胺通过 Buchwald-Hartwig 偶联反应制备。通过动电位极化研究和电化学阻抗谱测试了这些涂层抑制腐蚀的有效性。通过扫描电子显微镜（SEM）和原子力显微镜（AFM）对涂层的形貌进行了表征。涂层 AISI 4130 钢在 3.5 wt% NaCl 中的腐蚀测试表明，含吩噻嗪和咔唑的聚合物表现出优异的耐腐蚀性。吩噻嗪的保护效率 (PE) 为 95.9%，优于其他聚合物，包括聚苯胺涂层。 SEM图像表明，暴露于腐蚀性介质24小时后，聚合物仍然均匀地涂覆，具有稳定的形貌。这些结果表明，基于吩噻嗪和咔唑的 PANI 类似物可能是交通、航空、海洋以及石油和天然气工业应用中保护性有机涂层的候选材料。