Optimizing Heavy-duty Anticorrosive Performances of Coating Films Formed by Acrylate-vinylidene Chloride Copolymer Latexes through Twice-painting Technique

• Published in: Chinese journal of polymer science 2015, Vol.33 (1), p.14-22
• Main Authors: Fu, Ce, Zhang, Tong-xian, Ji, Cheng-qi, Cheng, Fa, Cui, Wen-zhu, Chen, Yu
• Format: Article
• Language: English
• Subjects: Acrylates; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Chlorides; Coating; Condensed Matter Physics; Corrosion; Corrosion tests; Industrial Chemistry/Chemical Engineering; Latex; Polymer Sciences; Protective coatings; Steels; 丙烯酸酯; 优化; 偏二氯乙烯; 共聚物胶乳; 喷漆技术; 涂层钢; 薄膜; 防腐性能
• ISSN: 0256-7679; 1439-6203
• DOI: 10.1007/s10118-015-1570-x

Twice-painting technique was adopted to prepare heavy-duty anticorrosive coating films formed by aqueous latexes of copolymers of vinylidene chloride（VDC） with an acrylate, namely methyl acrylate（MA）, ethyl acrylate（EA）, butyl acrylate（BA） or 2-ethylhexyl acrylate（EHA）. Harsh salt-spray corrosion tests demonstrated that the optimized twicepainting technique was that the acidic latex solution was adjusted to p H 5-6 for the first painting, while it was utilized directly for the second painting. The test of 600 h of harsh salt-spray corrosion showed that MA-VDC85 coating could protect the steel excellently, whereas the other acrylate-VDC coatings with 75%-90% VDC content could not protect the steel so effectively. Further corrosion test showed that（1） MA-VDC85 coating protected steel from loss of metallic luster for at least 1000 h of salt-spray corrosion;（2） adhesion of MA-VDC85 coating to steel was excellent for at least 800 h of saltspray corrosion, but became very poor after 1000 h. Differential scanning calorimetry, thermogravimetric analysis, X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy were used to evaluate the corroded MA-VDC85 film.