MDI/PPG型预聚体的合成研究

Research of MDI /PPG Prepolymer Synthesis

以4,4'二苯基甲烷二异氰酸酯(MDI)和聚丙二醇(PPG)2000为原料,通过测定反应过程中的NCO含量来确定反应终点,并结合IR分析,探讨了催化剂、预聚时间、反应温度对合成MDI型聚醚聚氨酯预聚体的影响。结果表明在T12作为催化剂,温度为75℃,预聚反应为2 h的实验条件下,不同的投料比均可以获得与理论NCO值接近的预聚体。研究不同物料比对产物粘度和储存时间的影响,确定物料比为3∶1时得到的预聚体粘度与稳定性最佳。MDI/PPG型预聚体与传统的预聚体相比,成本降低,异氰酸酯挥发性低,绿色环保,透明度高,将来会在胶黏剂预聚体中得到广泛的应用。

Using 4,4＇ - diphenylmethane diisocyanate （MDI） and polypropylene glycol （PPG） as main raw materials, the end of reaction are determined by detecting the content of the - NCO. Combined with IR analysis, the influence of catalyst, prepolymerization time and reaction temperature on the MDI polyether polyurethane prepolymer synthesis are studied. The experiments indicate different material ratios under conditions of T12 as catalyst, the reaction time is 2 h, the reaction temperature is 75℃ can all get theoret- ical NCO prepolymer. The impact of the material ratio on the viscosity and st orage time are researched, when material ratio is 3 ： 1, the prepolymer is best. compared with traditional prepolymer, MDI/PPG pre- polymer reduce production costs, low volatility, more environmentally friendly, high transparency, it would get more widely used in the polyurethme prepolymer filed.