一种基于没食子酸的锈转化涂料的合成及其性能

Synthesis and Properties of a Rust Conversion Coating Based on Gallic Acid

合成了一种基于没食子酸的弱酸型锈转化剂,在此基础上,结合了环氧树脂E-51、丁基缩水甘油醚、硅烷偶联剂(3-氨丙基三乙氧基硅烷)、固化剂T-31等制备出一种新型锈转化涂料。采用耐冲击性试验、附着力测试、电化学测试、扫描电子显微镜、盐雾试验和X射线衍射(XRD)等分别研究了锈转化涂层的耐蚀性、表面形貌、组成和耐蚀机理。结果表明:采用该锈转化涂料涂覆生锈20钢,得到的涂层表面光滑,且涂层和钢基体接触部位较为密实,表现出较强的黏附性;在盐雾试验和电化学测试中,该涂层表现出较好的耐蚀性;涂层所含有的酚羟基与铁离子螯合生成大分子铁化合物,进而抑制了铁锈进一步扩展。该锈转化涂料使用时,只需进行简单的表面浮锈处理,且能够做到一次涂覆完成,不需要采用传统的"底漆+面漆"的复杂工艺流程。

A weak acid rust converter based on gallic acid was synthesized.On this basis,a new type of rust conversion coating was prepared by combining epoxy resin E-51,butyl glycidyl ether,silane coupling agent(3-aminopropyl triethoxysilane),curing agent T-31 and so on.The corrosion resistance,surface morphology,composition and anti-corrosion mechanism of rust conversion coatings were studied by impact resistance test,adhesion test,electrochemical test,scanning electron microscopy,salt-spray test and X-ray diffraction(XRD).The results show that the rust conversion coating prepared on the surface of rusted 20 steel had a smooth surface,and the contact parts between the coating and the rusted steel were relatively dense,showing strong adhesion.The coating exhibited good corrosion resistance in salt-spray test and electrochemical test.Macromolecular iron compounds were formed by chelating the phenolic hydroxyl in the coating with Fe ion,which inhibited the further expansion of rust.When the rust conversion coating is used,it only needs simple surface floating rust treatment and can be completed by once coating,indicating that it is unnecessary to use traditional"primer+topcoat"complex process.