作　　者： ; ; ; ; ;

机构地区： 华南理工大学化学与化工学院

出　　处： 《热固性树脂》 2004年第6期1-4,共4页

摘　　要： 从聚氨酯预聚体分离游离的二异氰酸酯的方法有许多种,最好的方法是使用薄膜蒸发器进行分离。采用内冷凝式薄膜蒸发器和二次蒸馏技术研究了从甲苯二异氰酸酯(TDI)/三羟甲基丙烷(TMP)型聚氨酯预聚体分离游离TDI的方法及影响TDI分离的主要因素。研究工作通过使用MD-S80内冷式薄膜蒸发器,并调整蒸馏温度和真空度使产物中游离TDI低于0 5%。相应的蒸馏参数是:原料流速1 0kg/h,原料Ⅰ温度100℃,原料Ⅱ温度110℃,一次蒸馏温度150℃,二次蒸馏温度200℃,第一次蒸馏余压5000Pa,二次蒸馏余压35Pa;刮板转动速度150r/min。二次蒸馏后用醋酸丁酯稀释成质量分数为75%的溶液。预聚体中TDI质量分数为0 4%。异氰酸基含量高于12 7%,达到了分离的目标。结果表明内冷式薄膜蒸发器进行二次蒸馏有效地从TDI TMP预聚体分离了游离的TDI。 There were many ways to eliminate free diisocyanate from polyurethane prepolymer.The best way was to adopt thin-film evaporator to separate it.Separating free TDI from TDI-TMP polyurethane prepolymer was studied in the inner condensation wiped thin-film evaporator.The technique of distilling twice was adopted to separate toluene diisocyanate(TDI).Main factors,which had an effect on separating TDI,were studied.In this study,the content of TDI reduced to less than 0.5% through adjusting the temperature and the vacuum on the MD-S80 inner condensation thin-film evaporator.Appropriate distillation conditions were that the feed-in speed was 1.0 kg·h^(-1),the temperature of the first feed-in was 100 ℃,the temperature of the second feed-in was 110 ℃,the temperature of the first distillation was 150 ℃,the temperature of the second distillation was 200 ℃,the absolute pressure of the first distillation was 5 000 Pa,the absolute pressure of the second distillation pressure was 35 Pa,and the rotating speed of the scraping plank 150 r·min^(-1).After distilling twice,the polyurethane prepolymer was diluted to 75% solution through adding butyl acetate.The concentration of TDI in the prepolymer was 0.40%,and the content of NCO was more than 12.7%.The goal of separating TDI from TDI-TMP polyurethane prepolymer was attained.It is feasible to separate TDI from TDI-TMP polyurethane prepolymer with the inner condensation wiped thin-film evaporator through distilling twice.

关 键 词： 内冷凝式薄膜蒸发器 分离 聚氨酯 预聚体

领　　域： [化学工程]