ABSTRACT

The effect of ethyl cellulose (EC) micro/nanocapsules containing linseed oil (LO) on the cathodic disbonding of self-healing composite coatings is investigated by cathodic disbonding test and electrochemical impedance spectroscopy (EIS). Results reveal that the presence of EC nanocapsules significantly improves the cathodic disbonding resistance of the coatings so that the rates of disbonded area under the simulated condition of cathodic protection decrease from 3.882 mm² h for the blank coating to 0.025 mm² h for the nanocapsules containing coating. It may be ascribed to the releasing LO and filling the defects at the coating/substrate interface by oxidative polymerisation mechanism. EIS test results indicate that the corrosion resistance of the coatings is improved in the presence of EC nanocapsules. In addition, the coating resistance to cathodic disbonding and corrosion increase by decreasing capsule sizes. Finally, a proposed mechanism of ion diffusion through the self-healing coating’s defect is schematically illustrated.

摘要

通过阴极剥离试验和电化学阻抗谱（EIS）研究了含有亚麻籽油（LO）的乙基纤维素（EC）微/纳米胶囊对自修复复合涂层阴极剥离的影响。结果表明，EC纳米胶囊的存在显着提高了涂层的抗阴极剥离能力，使得模拟阴极保护条件下的剥离面积率从空白涂层的3.882 mm ² h降低到0.025 mm ²h 对于含有涂层的纳米胶囊。这可能归因于释放 LO 并通过氧化聚合机制填充涂层/基材界面处的缺陷。EIS 测试结果表明，EC 纳米胶囊的存在提高了涂层的耐腐蚀性。此外，通过减小胶囊尺寸，涂层对阴极剥离和腐蚀的抵抗力增加。最后，示意性地说明了通过自修复涂层缺陷的离子扩散机制。