水性转锈防腐乳液的合成与性能研究

Study on Synthesis and Performance of Waterborne Rust Conversion Anticorrosive Emulsion

以没食子酸为原料与1,2-丙二醇反应合成具有转锈作用的络合剂单体,以P2O5为原料与甲基丙烯酸-β-羟乙酯反应合成具有抗闪蚀作用的磷酸酯功能单体,再添加甲基丙烯酸甲酯、丙烯酸丁酯等原料,采用预乳化-半连续种子乳液合成方法,制备一种水性带锈转锈聚合物乳液。通过扫描电镜(SEM)、能量分析光谱仪(EDX)、X射线光电子能谱仪(XPS)及X射线粉末衍射仪(XRD)表征铁锈与转锈剂作用的产物及其膜的防腐性能。通过交流阻抗、Tafel极化曲线及一般理化性能分析考察水性转锈乳液的成膜性能及其对钢铁的防腐性能的影响。结果显示:转锈剂与铁锈作用生成转化膜并附着在基材表面,膜层1 h内变黑,表明转锈剂与铁锈有效作用且对钢铁的防腐性能良好;水性转锈乳液涂膜附着力2级,铅笔硬度HB,耐盐雾72 h;随浸泡时间的延长,涂层的容抗弧直径变大,涂层电阻也相应变大,耐腐蚀性呈增强趋势;乳液粒径为30.31 nm,呈单峰分布,强度大且峰形窄,粒径分布指数比较小,说明乳液粒径分布均一,附着性良好;转锈后锈层表面平整、结构紧密,可以有效阻止锈蚀;各项指标结合说明涂层成膜性能良好且防腐效果好。

The P2O5 as phosphorylation agent was reacted with hydroxyethyl methacrylate ester（HEMA） at the presence of rust conversion agent which was synthesized by using gallic acid and 1,2-propanediol to form a phosphate ester functional monomer, which was further mixed with methyl methacrylate, butyl acrylate, haloalkene, etc. to prepare a waterborne rust conversion anticorrosive polymer emulsion via a seed emulsion polymerization method. The products derived from reaction of rust and rust conversion agent and film properties were char- acterized by SEM, EDX, XPS and XRD. Meanwhile, the properties of emulsion were studied by alternating current impedance and tafel polarization curve and other physicochemical analy- sis. The results showed that the rust on the surface of the steel could react with rust conversion agent to form a film which became black with 1 h and provided good anticorrosive performance.The rust conversion film exhibited adhesion grade 2, pencil hardness HB; salt fog resistance 72 h by means of immersion in 3.5% NaCl aqueous solution. With the increase of the immer- sion time, the capacitive reactance arc diameter of the film increased accordingly, meanwhile, the resistance and anticorrosion of the film increased. The emulsion particle size was 30. 31 nm and its distribution perk was narrow, single and strong, indicating that there was a uniform particle size distribution, the adhesion was good. Furthermore, the rust conversion film had an even and dense surface structure with good rust resistance. All test results showed that the e- mulsion had good film-forming performance and anticorrosive property.