通过检测不同大气环境中曝晒后丙烯酸聚氨酯涂层的光泽度、吸水率、涂层/金属间结合强度、涂层的耐盐雾腐蚀性和界面电化学腐蚀特征,研究武汉和拉萨地区大气环境对丙烯酸聚氨酯涂层耐蚀性能的影响。结果表明,丙烯酸聚氨酯涂层在拉萨大气环境中老化程度相对较为严重。在拉萨地区涂层主要以光降解方式老化,而在武汉地区涂层以光降解和水降解方式老化;在拉萨地区,涂层阻挡腐蚀性介质能力下降较为明显,曝晒12个月后涂层的界面电极电化学反应由扩散步骤控制,而在武汉地区该反应主要由电化学步骤控制。
Effect of different climates on anti-corrosion of acrylic/polyurethane coating have been studied in this paper. Anti-corrosion of the coatings after exposed at Wuhan and Lasa were evaluated by gross loss rate, water absorption rate, rupture strength, salt spray test and EIS. The results showed that coating exposed in Lasa aged more severely than in Wuhan, accordingly anti-corrosion of coating in Lasa lost more badly than that in Wuhan. The main way of the degradation of the coating exposed in Lasa was photo-oxidation degradation. However the way of the degradations of the coating exposed in Wuhan were photo-oxidation and hydrolytic degradation. The capability of the coating exposed in Lasa to prohibit corrosive media through coating lost more badly than that in Wuhan. The electrochemical reaction rate, which was produced on the interface, was controlled by diffusion step after the coating was exposed in Lasa for 12 months. However, the electrochemical reaction rate was controlled by electrochemical step in Wuhan.