金属表面环氧聚氨酯涂层的去除机理研究

Study on Removing Mechanism of Epoxy & Polyurethane Film on Metal Surface

以飞机上常用的环氧、聚氨酯涂料为研究对象,通过溶剂对涂层的作用、红外光谱测试和热重分析等方法,研究水溶性去漆剂对金属表面交联固化涂层的去除机理。实验及研究结果发现,去漆剂去除涂层要有溶胀涂层的溶剂,还要有渗透力强的溶剂;涂层脱除过程中,去漆剂的溶剂分子与涂层高分子之间没有发生化学反应,去漆剂对涂层高分子链段无降解破坏作用,而是使高分子链段网状结构扩大,使涂层膨胀鼓起,与金属基材分离;根据溶解度参数原则,固化后涂层的溶解度参数与固化前树脂的溶解度参数及去漆剂的溶解度参数相比较,得出应该根据涂层固化后的溶解度参数来选择溶胀涂层的溶剂,而不是沿用涂层固化前树脂的溶解度参数来设计去漆剂。

On based of epoxy or polyurethane coatings commonly used in airplane, the removing mechanism of water-based remover to cross-linking cured coatings on metal surface was studied through analysis of effect of solvents combinations of stripper on coatings, IR test and TG anlysis. The results show that the stripping of remover is due to the combining effect of agents, not only solvents of swelling, but also solvents of penetration, another is that the molecules between stripper and coatings don＇ t happen chemical reaction, and the molecules of stripper don＇ t destroy polymer segment, but make the polymer molecules network structure swelling. At last, on based of the rules of solubility parameters, through the compare of solubility parameters of resin and coating, concludes that should select solubility parameters of curing coating to choose solvents which can make the coating swelling, but not the solubility parameters of resin.