本征态聚苯胺/环氧有机硅复合涂层的防腐性能

目的研究本征态聚苯胺/环氧有机硅复合涂层在Na Cl溶液中对Q235低碳钢的防腐效果。方法以自制的本征态聚苯胺为防腐颜料,按比例加入填料及助剂,砂磨分散后制备质量分数为0.5%、1.0%及1.5%的本征态聚苯胺/环氧有机硅复合涂层。Q235钢板经砂纸打磨后去油除渍,采用喷涂方式涂覆制备涂层样品。利用扫描电子显微镜观察不同添加量的本征态聚苯胺在环氧有机硅涂层中的分散状态,涂层在质量分数为3.5%的Na Cl溶液浸泡不同时间,采用X射线光谱分析涂层浸泡后的物相,并通过开路电位和电化学阻抗谱对比分析涂层的耐腐蚀性能。结果本征态聚苯胺/环氧有机硅复合涂层中EB添加量(质量分数)为1.0%时,颗粒分散较均匀且能促进形成致密的氧化钝化膜,浸泡后期的涂层表面微孔电阻值较高(Rpo=3.89×106Ω·cm2),表现出良好的电化学性能;添加量(质量分数)为0.5%时颗粒分散较稀疏,涂层的阻抗值和拟合电阻值均下降;添加量(质量分数)为1.5%时涂层的阻抗值和拟合电阻值较小,腐蚀速度不断加快。结论本征态聚苯胺添加量(质量分数)为1.0%时,其在环氧有机硅涂层的分散均匀且致密,并在3.5%的Na Cl溶液中浸泡后对Q235低碳钢表现出良好的防腐效果。

Anti-corrosion Performance of EB/ Epoxy-silicone Composite Coatings

ABSTRACT:Objective To investigate the anti-corrosion performance of EB/epoxy-silicone composite coatings on Q235 mild steel in sodium chloride medium. Methods The epoxy-silicone composite coatings were prepared using the self-made anti-corrosion pig-ment of EB, with proportional addition of fillers and additives, after sanding dispersion, EB/epoxy-silicone composite coatings with mass fractions of 0. 5%, 1. 0%, 1. 5% were obtained. Q235 mild steel was handled by sandpapering to remove the oil, and the coatings were prepared by spraying method. SEM tests were carried out to observe dispersed state of different quantities of EB in the epoxy-silicone composite coatings. X-ray diffraction was used to analyze the phase of the coatings after immersion in 3. 5% NaCl solution for different time, and the anti-corrosion properties were studied by means of open circuit potential and electrochemical im-pedance spectroscopy. Results When the content of EB in EB/ epoxy-silicone composite coating was 1. 0%, the particles were e-venly dispersed and the formation of dense passive oxide film was promoted. The microporous resistance value (Rpo=3. 89×106Ω· cm2 ) on the surface of coatings was higher after soaked, which exhibited excellent electrical chemical properties. When the content of EB was 0. 5%, the particles were dispersed relatively sparsely, and the impedance values and fitting resistance values of the coatings decreased. When the content of EB was 1. 5%, the impedance values and fitting resistance values of the coa-tings were lower, and the corrosion rate continued to accelerate. Conclusion EB were uniformly and densely dispersed in the coa-ting with 1. 0% EB, and the coating had the best anti-corrosion performance on Q235 mild steel in NaCl (3. 5%) solution.