还原剂对锌基水性耐蚀涂层性能的影响

EFFECTS OF THE REDUCTANT ON THE ZINC-BASED WATERBORNE ANTICORROSIVE COATING

采用胶带剥离、硝酸铵快速腐蚀、热失重分析和电化学等方法研究了丙烯酸、丁二酸、丙三醇和葡萄糖等4种还原剂及其含量对锌基水性涂层结合强度和耐蚀性能的影响,并与普通镀锌件对比.结果表明,还原剂种类和用量均显著影响涂层的结合强度和耐蚀性能,以丙烯酸作还原剂,在较大成分范围内涂层具有高的结合强度,而丁二酸、丙三醇、葡萄糖作还原剂时只有在低含量下涂层结合性能优良.涂层耐腐蚀时间随还原剂含量的增加均出现先增大后减小的趋势.以丙烯酸或丙三醇为还原剂制备的涂层综合性能优异,最佳用量分别为60 g/L和20 g/L.涂层由多层片状锌粉和黏结物质组成,在不同腐蚀环境中均表现出优异的耐蚀性能.热力学计算结果表明,4种还原剂固化反应均可在烧结温度下进行.

The effects of four kinds of reductaats, acrylic acid, succinic acid, glycerol, glucose, and their contents on the bonding strength and anticorrosion of zinc-based waterborne anticorrosive coatings were studied through adhesive tape test, ammonium nitrate solution accelerated corrosion method, electrochemical measuremeat, thermogravimetric and comparison with zinc plating. The experimental results indicate that variety and content of the reductants had markedly influenced on the bonding strength and corrosion resistance of coatings. Using acrylic acid as the reductant the coatings had high bonding strength in a large adding range, and it can hold high bonding strength when the other reductants had low content. The corrosion resistance time increases firstly, and then decreases with the increment of reductant content. The coatings with acrylic acid or glycerol as reductant had good comprehensive properties, optimal dosage were 60 g/L and 20 g/L respectively. The coatings are composed of multilayer flake zinc powder and cement substance, and the corrosion resistance performances are obviously superior to zinc plating under different environmental conditions. Moreover, the formation mechanism of coatings is analyzed, thermodynamical calculation shows that all the cure reactions using these reductants can proceed automatically at solidifying temperature.