水性丙烯酸胶黏剂中消泡剂消泡机理的研究

Study on Defoaming Mechanism of Defoamer in Waterborne Acrylic Adhesive

通过分析有机和分子级消泡剂在起泡液和水性丙烯酸胶黏剂乳液中的性能,考察了添加工艺和测试方法对消泡剂消泡性能的影响,探讨了消泡剂的消泡机理,综合选出了最适合水性丙烯酸胶黏剂乳液的消泡剂.结果表明:消泡剂的相容性和消泡能力成反比;在极短时间范围内,0.2%用量的消泡剂在起泡液中的动态吸附过程由扩散控制;分子级消泡剂适用于"架桥-铺展"机理,而有机消泡剂适用于"架桥-铺展"和"架桥-脱湿"机理;消泡剂的加入对水性丙烯酸胶黏剂乳液的黏度、粒径和存储稳定性无显著影响.

The most suitable defoamer for water-based acrylic adhesive was chosen by analyzing the property of organic and molecular defoamer in the foaming solution and waterborne acrylic emulsion. Adding process and test methods of the antifoaming performance and defoaming mechanism were investigated. The results show that the compatibility of the defoamer is inversely proportional to the defoaming ability. Dynamic adsorption of 0.2% defoamer in foaming solution is diffusion controlled in short time. Molecular level defoamers are suitable for "bridging-stretching" mechanism while organic defoamers are suitable for both "bridging-stretching" and "bridging-dewetting" mechanisms. The addition of defoamer has no notable effect on the viscosity, particle size and storage stability of waterborne acrylic adhesive emulsion.