摘要
采用工艺与装备一体化的思路进行了TDI-TMP聚氨酯固化剂的合成与分离研究。研究了适合在薄膜蒸发器中进行游离TDI分离的聚氨酯预聚物的合成工艺,讨论了TDI/TMP的配比、反应温度和加料方式对TDI-TMP预聚物合成工艺的影响。研究了高真空两级薄膜蒸发器分离预聚物中游离TDI的分离工艺,讨论了进料速率、二级蒸馏温度、二级绝对压力和二级刮板转速对分离效果的影响。研究表明:在TDI与TMP质量比在5:1,反应温度在50℃,反应时间5h的合成条件下,得到的预聚物分子量小、黏度低、流动所需温度低,适合在薄膜蒸发器中进行游离TDI的分离。优化的分离工艺条件是进料速率为1.6kg·min-1,二级蒸馏温度为170℃,二级蒸馏绝压为80Pa,二级刮板转速为180r·min-1。合成与分离后的聚氨酯固化剂色泽浅、游离TDI含量和-NCO含量符合设计要求。
The synthesis of TDI-TMP polyurethane curing agent which is suitable for distilling free TDI from the polyurethane prepolymer with two stage thin film evaporator was studied. The factors influencing the TDI-TMP addition reaction,such as the TDI/TMP ratio,reaction temperature and feeding mode,were discussed. A two stage thin film evaporator was used for the separation of free TDI from the TDI-TMP prepolymer. The factors influencing the TDI separation,such as the feeding rate,temperature and pressure of separation and the speed of the scraping plank in the second stage thin film evaporator,were investigated. The results show that,with the TDI/TMP mass ratio of 5：1 and the reaction time of 5 h at 50℃,the TDI-TMP prepolymer synthesized can have small molecular mass and low viscosity,which is more suitable for the separation of the free TDI from it by film evaporation. Moreover,the optimize separation conditions of using thin film evaporation to remove the free TDI were found as follows：the feeding rate is 1.6 kg·min^-1,the temperature and pressure of the second stage evaporator are 170℃ and 80 Pa,respectively. After synthesis and free TDI separation under above conditions,the contents of free TDI and -NCO in the prepared TDI-TMP polyurethane curing agent can meet the required demand.
出处
《高校化学工程学报》
EI
CAS
CSCD
北大核心
2009年第5期807-812,共6页
Journal of Chemical Engineering of Chinese Universities
