摘要： 以甲苯二异氰酸酯(TDI)、聚乙二醇400(PEG-400)为主要原料,合成端异氰酸酯基的聚氨酯预聚体,以亚硫酸氢钠为封闭剂,对预聚体进行了封闭研究。着重考察了封闭反应温度、溶剂配比、促进剂、亚硫酸氢钠用量和浓度、p H等对封闭率的影响。用FT-IR和DSC对产物进行了表征分析,结果显示:在最优条件下,实现了亚硫酸氢钠对端异氰酸酯基的良好封闭,产物的解封温度在56.3~68.4℃之间。
关键词:
水性聚氨酯,
亚硫酸氢钠,
封闭反应,
解封闭反应
Abstract: A polyurethane prepolymer terminated with -NCO groups was synthesized from TDI and PEG-400 as main raw materials and then the prepolymer was blocked with sodium bisulfate as blocking agent. The effect of blocking temperature, solvent ratio, dosage and mass fraction of sodium bisulfate, promoting agent amount and pH value on blocking rate were discussed. The products were characterized by FT-IR and DSC. The experimental results showed that the good blocking rate of isocyanate by sodium bisulfate could be realized under optimal conditions, additionally the deblocking temperature determined by DSC was approx.56.3~68.4℃.
Key words:
water-borne polyurethane,
sodium bisulfate,
blocking reaction,
deblocking reaction
胡 鹏, 贺龙强, 刘中阳, 何伟国. 封闭型水性聚氨酯的制备及表征[J]. 涂料工业, 2014, 44(10): 38-42.
Hu Peng, He Longqiang, Liu Zhongyang, He Weiguo. Preparation and Characterization of Waterborne Blocked Polyurethane[J]. Paint & Coatings Industry, 2014, 44(10): 38-42.