分子蒸馏法从异氰酸酯热解液中分离多亚甲基多苯基多异氰酸酯

采用分子蒸馏技术从异氰酸酯热解液中分离多亚甲基多苯基多异氰酸酯(PMPPI)，通过设计L25(56)正交实验对PMPPI-氯苯的模拟热解液进行分离，得到最佳工艺条件为：进料速度2 mL/min、蒸馏温度100℃、转子速度120 r/min、蒸馏压强4.0 kPa，该条件下PMPPI的分离纯度高达99.65%. 使用上述最佳分离条件对多亚甲基多氨基甲酸甲酯(PMDC)热解分离PMPPI的真实热解液进行分离，分离高效液相色谱检测不到氯苯，证明分子蒸馏可从异氰酸酯热解液中高效分离PMPPI.

Separation of Polymethylene Polyphenyl Polyisocyanate (PMPPI) from the PMPPI-Chlorobenzene Pyrolysis Liquid Using Molecular Distillation

Molecular distillation was used to separate polymethylene polyphenyl polyisocyanate (PMPPI) from PMPPI-chlorobenzene pyrolysis liquid via orthogonal experiments using an OA25(45) design, the optimal separation conditions of the simulated PMPPI- chlorobenzene solution were determined as feed flow rate 2 mL/min, distillation temperature 100℃, wiper rotating speed 120 r/min and distillation pressure 4.0 kPa. Under the optimal conditions, the purity of PMPPI reached as high as 99.65%. Finally, the real PMPPI- chlorobenzene pyrolysis liquid was separated using the above optimal conditions, chlorobenzene could not be detected in the final product with HPLC analysis, indicating that the purity of PMPPI approached to 100%.