Blocked polyurethane prepolymer and preparation method thereof

The invention relates to a blocked polyurethane prepolymer and a preparation method thereof. The preparation method comprises the following steps: preparing an isocyanate-terminated polyurethane prepolymer from single hydroxyl-terminated polyvinylpyrrolidone and polyisocyanate; and then, using a sealing agent for sealing an isocyanate-terminated group of the isocyanate-terminated polyurethane prepolymer to form the water-soluble blocked polyurethane prepolymer, wherein the sealing agent is N-(3-formyl-4-hydroxybenzyl)-N,N,N-trialkylammonium chloride; and the blocked polyurethane prepolymer disclosed by the invention is soluble in water, high in stability and convenient to store and transport, and the sealing agent has the characteristics of hydrophilicity, sterilization and oxidation resistance. 本发明涉及一种封闭型聚氨酯预聚物及其制备方法，是由单端羟基聚乙烯吡咯烷酮与多异氰酸酯制成端异氰酸酯基聚氨酯预聚物，再使用封闭剂对所述端异氰酸酯基聚氨酯预聚物的端异氰酸酯基进行封闭而成的可溶于水的封闭型聚氨酯预聚物；所述封闭剂指的是氯化N-(3-甲酰基-4-羟基苄基)-N,N,N-三烃基铵；本发明所述封闭型聚氨酯预聚物可溶于水，稳定性高，便于储存运输，所述封闭剂具有亲水杀菌抗氧化的特性。