【摘要】 本文对影响薄膜蒸发器分离聚氨酯TDI-TMP预聚体中游离TDI的各操作条件进行了分析研究,得出了要获得TDI含量低于0.5wt%的TDI-TMP预聚体所需的较优化的操作条件。TDI-TMP预聚体在MD-S80内冷式薄膜蒸发器中分离的较优化操作条件为:初级蒸发温度为140℃,初级蒸发真空度为400 Pa,次级蒸发温度为160℃,次级蒸发真空度为40Pa,刮板转速均为180 r/min,进料温度为100℃,进料速度12.0 g/min,经两级分离后,将蒸余物与分析纯的醋酸丁酯混合,配成固含量75wt%的固化剂,其TDI含量小于0.50wt%,-NCO含量为13.0±0.2wt%。更多还原

【Abstract】 This paper summarized the major factors which affected the process of double-stage separating TDI from polyurethane prepolymer by thin film evaporator and the optimum conditions under which proceeding separation procedure.The better optimized operation conditions were obtained to get the low TDI contamination in TDI-TMP prepolymer,which was less than 0.5wt%.The optimum conditions of TDI-TMP preolymer separation in MD-S80 thin film evaporator were as following: temperatures of first-stage evaporation and second-stage were 140℃ and 160℃,pressure were 400 Pa and 40 Pa,rotate speed of scraping plank was 180 r/min,feeding speed was 12.0 g/min,with temperature 100℃.At last the product of polyurethane prepolymer was obtained with perfect quality,the remaining free TDI was less than 0.5 wt%,solid content and –NCO content of prepolymer were 75 wt% and 13±0.2 wt% respectively.更多还原