海洋环境腐蚀与生物污损重点实验室知识库

随着在役钢结构不断进入服役维修期，能够在未充分除锈的钢铁表面上进行涂装且符合环保趋势的水性锈转化涂料具有广阔的应用前景。开发有效的转锈剂成分及其水性锈转化涂料配方，深入了解其作用原理及适用条件，能够为在役设施防腐维护提供重要技术支撑。

基于上述背景，本文以恒温恒湿法所制带锈钢作为研究对象，探索了转锈剂复配及锈转化涂料的制备。结果表明，所获带锈钢的成分及结构与碳钢大气腐蚀较为相似，是锈转化研究理想的对象。将没食子酸与磷酸复配并搭配合理的成膜助剂、消泡剂，能够应用于氯乙烯基-丙烯酸乳液中制备有效的水性锈转化涂料。

系统研究了磷酸-没食子酸在氯乙烯基-丙烯酸乳液中的转锈性能和机理。结果表明该涂料能够有效处理恒温恒湿法模拟海洋大气腐蚀所制备的带锈钢，形成有良好的附着力和防腐性能的黑色转化膜。转化产物为磷酸铁和没食子酸铁，没食子酸铁在膜层中分布均匀，磷酸铁聚集在转化膜内和未转化锈蚀表层。基体与转化膜间未转化铁锈限制了附着力和防腐性能的进一步提高。

进一步研究了该涂料在不同结构锈面上的应用效果。结果表明，盐雾腐蚀试验与沿海户外曝露所制带锈钢的浮锈都为均匀锈面。不同的是，盐雾腐蚀所得附着锈层分布不均，而户外曝露所获附着锈层分布均匀。磷酸-没食子酸基锈转化涂料在盐雾腐蚀所制带锈钢上形成的不均一转化膜，存在大量微小孔洞，耐蚀性较差。其在户外曝露所制带锈钢上成膜均匀，在涂层完整的情况下具有较好的防腐性能。然而，该转化膜下仍存在未转化铁锈，一旦涂层出现破损，腐蚀则会较快发生。因此，锈转化涂料只有在均匀的附着锈层上实现较为彻底的锈转化，才能获得最佳的转锈防腐效果。

本文制备了一种磷酸-没食子酸基水性锈转化涂料，深入研究了该涂料的防腐效果、转锈机理及适用条件。为更合理的开发基于没食子酸及其衍生物所配制的锈转化涂料提供了一定的理论和实验依据。

There are anti-corrosion maintenance problems in the service of steel equipment. Water-based rust conversion coatings (RCC) conform to the trend of environmental protection and have broad application prospects. Exploring effective water-based RCC, and clarifying its principle of action and applicable conditions can provide important technical support for the anti-corrosion of in-service facilities and equipment.

This thesis takes the rusted steel (RS) prepared by the constant temperature and humidity (CTH) method as the research object, and explores the preparation of rust converter (RC) and RCC. The results show that the composition and structure of the obtained rusted steel are similar to the atmospheric corrosion of carbon steel. Therefore, it is an ideal object for the research of RCC. Adding gallic acid (GA) and phosphoric acid (PA) to the vinyl chloride-acrylic acid emulsion with a reasonable film-forming aid and defoamer can prepare effective water-based RCC.

The rust conversion performance and mechanism of phosphoric acid-gallic acid in vinyl chloride-acrylic emulsion were systematically studied. The results show that the RCC can effectively treat the RS prepared by CTH method, and can form a black conversion film with good adhesion and anti-corrosion properties. The conversion products are ferric phosphate and ferric gallate. The ferric gallate is evenly distributed in the film, and the ferric phosphate accumulates in the rust conversion film (RCF) and on the surface of unreacted rust. The unreacted rust between the substrate and the conversion film limits the further improvement of adhesion and corrosion resistance.

The application effect of the RCC on the rusty surface of different structures was further studied. The results show that the nonadherent rust (NAR) of the RS prepared by salt spray corrosion test (SSCT) and coastal outdoor exposure (COE) is uniform and complete. The difference is that the adherent rust (AR) layer prepared by SSCT is unevenly distributed, while the AR layer obtained by COE is evenly distributed. The RCC forms a non-uniform RCF with many micropores on the RS prepared by SSCT, and has poor corrosion resistance. This RCC can form a uniform RCF on the surface of the RS prepared by COE, and has good anti-corrosion performance when the coating is intact. However, there is still unreacted rust under the RCF, and corrosion will occur quickly once the coating is damaged. Therefore, the RCC can achieve the best rust conversion and anti-corrosion effect only by achieving more thorough rust conversion on the evenly AR layer.

In this paper, a waterborne RCC based on PA and GA was prepared, and the anti-corrosion effect, rust conversion mechanism and applicable conditions of this coating were deeply studied. The above research provides some theoretical and experimental basis for the more reasonable development of RCC based on gallic acid and its derivatives.