以聚四氢呋喃二醇、聚己二酸丁二醇酯二醇、异氟尔酮二异氰酸酯、非离子型亲水单体MO3和液体石蜡等为原料,制备了端基为-NCO基团的聚氨酯预聚体自乳化细乳液,以改进的丙酮/甲苯-二正丁胺法测定细乳液体系中-NCO基团的含量,采用红外光谱表征了自乳化细乳液中水解产物的结构;根据假设建立了细乳液中-NCO基团的水解反应模型,在不同温度和亲水单体MO3用量下对该模型进行了拟合.结果表明:聚氨酯预聚体自乳化细乳液的水解产物为聚氨酯-聚脲共聚物,拟合结果与水解反应模型的假设相符,自乳化细乳液体系中-NCO基团水解反应的表观活化能为60.2 kJ·mol-1,且水解反应速率随着亲水链段含量的升高而加快.

The self-emulsifying miniemulsion of polyurethane prepolymer with terminal groups of isocyanate (-NCO) was prepared using polytetrahydrofuran glycol,polyethylene glycol adipate,isophorone diisocyanate,non-ionic hydrophilic monomers of MO3 and liquid paraffin.The content of -NCO groups in miniemulsion was determined by modified acetone/toluene-dibutylamine titration method,and the structure of hydrolysate in self-emulsifying was characterized by FTIR.The model of hydrolysis reaction of -NCO groups was also established based on some assumptions,and was fitted under the conditions of different temperatures and different amounts of MO3.The results show that the hydrolysate was poly(urea-urethane).The fitting results fitted well with the physical model,in self-emulsifying miniemulsion,the apparent activation energy of hydrolysis reaction of -NCO groups was 60.2 kJ·mol-1,and the hydrolysis reaction rate was accelerated by the increase of the content of hydrophilic chain segment.