Molecular distillation was used to recover ionic liquid(IL) 1-allyl-3-methylimidazolium chloride(AmimCl) in homogeneous cellulose acetylation.The five factors that affect the separation efficiency of molecular distill...Molecular distillation was used to recover ionic liquid(IL) 1-allyl-3-methylimidazolium chloride(AmimCl) in homogeneous cellulose acetylation.The five factors that affect the separation efficiency of molecular distillation,namely,feed flow rate,distillation temperature,feed temperature,wiper rotating speed,and distillation pressure,are discussed.The optimal recovery condition was determined via orthogonal experiments using an OA9(34) design.The IL was recycled and reused 5 times in the homogeneous cellulose acetylation system under optimal conditions.The purity of recycled IL the 5th time reached 99.56%.FT-IR(Fourier transform infrared spectroscopy) and 1H NMR(nuclear magnetic resonance) spectroscopy showed that the structure of the recovered IL is not changed.This work proves that AmimCl has excellent reusability,and that molecular distillation is an effective method for recovering IL in homogeneous cellulose acetylation.展开更多
Although many ionic liquids have been reported, their polarity is not completely understood. Different empirical polarity scales for molecular solvents always lead to different polarity orders when they are applied on...Although many ionic liquids have been reported, their polarity is not completely understood. Different empirical polarity scales for molecular solvents always lead to different polarity orders when they are applied on ionic liquids. Based on a literature survey, this review summarizes the recent polarity scales of ionic liquids according to the following 4 classes:(1) equilibrium and kinetic rate constants of chemical reactions;(2) empirical polar parameters of ionic liquids;(3) spectral properties of probe molecules;(4) multiparameter approaches. In addition, their interrelations are presented. A systematic understanding of the relationship between different polarity parameters of ionic liquids is of great importance for finding a universal set of parameters that can be used to predict the polarities of ionic liquids quantitatively. The potential utilization of the electron paramagnetic resonance in this field is also addressed.展开更多
基金Supported by the Major Project of the State Key Development Program for Basic Research of China（2009CB219901）the National Natural Science Foundation of China（21006118）
文摘Molecular distillation was used to recover ionic liquid(IL) 1-allyl-3-methylimidazolium chloride(AmimCl) in homogeneous cellulose acetylation.The five factors that affect the separation efficiency of molecular distillation,namely,feed flow rate,distillation temperature,feed temperature,wiper rotating speed,and distillation pressure,are discussed.The optimal recovery condition was determined via orthogonal experiments using an OA9(34) design.The IL was recycled and reused 5 times in the homogeneous cellulose acetylation system under optimal conditions.The purity of recycled IL the 5th time reached 99.56%.FT-IR(Fourier transform infrared spectroscopy) and 1H NMR(nuclear magnetic resonance) spectroscopy showed that the structure of the recovered IL is not changed.This work proves that AmimCl has excellent reusability,and that molecular distillation is an effective method for recovering IL in homogeneous cellulose acetylation.
基金supported by the National Natural Science Foundation of China (21573196)the Program for Zhejiang Leading Team of S&T Innovation (2011R50007)the Fundamental Research Funds of the Central Universities
文摘Although many ionic liquids have been reported, their polarity is not completely understood. Different empirical polarity scales for molecular solvents always lead to different polarity orders when they are applied on ionic liquids. Based on a literature survey, this review summarizes the recent polarity scales of ionic liquids according to the following 4 classes:(1) equilibrium and kinetic rate constants of chemical reactions;(2) empirical polar parameters of ionic liquids;(3) spectral properties of probe molecules;(4) multiparameter approaches. In addition, their interrelations are presented. A systematic understanding of the relationship between different polarity parameters of ionic liquids is of great importance for finding a universal set of parameters that can be used to predict the polarities of ionic liquids quantitatively. The potential utilization of the electron paramagnetic resonance in this field is also addressed.
