Catalytie Synthesis Of Ethyl Laurate By Using Immobilized Ionic Liquid

Esterification is a typical acid catalyzed reaction,and product esters are often used as perfumes and solvents.The ethyl laurate for its natural fruit flavor,commonly used spices,fixative and diluent in liquid food,semi solid food and solid food in a wide range of applications,can also be used for fragrance formula,can also be used as lubricants,plasticizers and softener.The potential market demand for ethyl laurate has attracted much attention in its synthesis and preparation.In this paper,a series of acidic ionic liquids and immobilized ionic liquids have been synthesized,and using FT-IR,TGA,BET and Solid state 31P MAS NMR to characterize catalyst structure.At the same time,the various factors on the esterification were investigated,and response surface methodology was used to optimize the reaction conditions,and the reaction kinetics model was established.In the second chapter,a series of acidic ionic liquids were prepared,and their structures and catalytic activities were investigated.Research shows that Br(?)nsted Acid Ionic liquid,Bronsted-Lewis acid ionic liquid showed good catalytic activity in the preparation process of ethyl laurate,which is associated with strong acid and the synergistic effect of B-L acid.Among them,the[DMBPSH]HSO4 catalyst is compared with other Br(?)nsted catalyst has the best catalytic performance.Using[DMBPSH]HSO4 as catalyst,the optimum conditions for the synthesis of lauric acid ethyl ester by response surface methodology were as follows:the molar ratio of acid to alcohol was 5.8:1,the amount of catalyst was 3.1wt%,the reaction temperature was 383K,and the reaction time was 2.3 h.Under these conditions,the yield of lauric acid ethyl ester was 95.4%.Under the optimum conditions,reaction order for synthesizing ethyl laurate is 1.55,the activation energy of reaction is 37.60 kJ/mol,the reaction r=-dCA/dt=7.28×103exp(-37.60/RT)CA1.55kinetic equation is as follows:In the third chapter,the immobilized Lewis acidic ionic liquid was prepared,and its structure and catalytic activity were investigated.The results show that 20%immobilized CrCl3 ionic liquid catalyst(20%[Bmim]Cl-CrCl3/SG)has the best catalytic esterification activity,and the catalytic activity is improved when the catalyst is not loaded.The optimum reaction conditions for the preparation of lauric acid ethyl ester with 20%[Bmim]Cl-CrCl3/SG was used as catalyst are:the molar ratio of acid to alcohol is 10.5:1,the amount of catalyst is 3.1 wt%,the reaction temperature is 383 K,the reaction time is 4.6h.Under this condition,the yield of lauric acid ethyl ester is 90.1%.Under the optimum conditions,reaction order for synthesizing ethyl laurate is 1.19,the activation energy of reaction is 21.32 kJ/mol,the reaction kinetic equation isr-=dCA/dt=13.7.6exp(-21.32/RT)CA1.19 as follows:In the fourth chapter,Br(?)nsted-Lewis acidic ionic liquid[DMBPSH]+(1/2Cu2+)SO42-as parent integrant to synthetic different amounts of immobilized B-L catalyst[DMBPSH]+(1/2Cu2+)SO42-/SG,and to investigate its structure and catalytic activity.The results show that the immobilized B-L acidic ionic liquid catalyst with 20%loading exhibits good catalytic performance.Using the[DMBPSH]+(1/2Cu2+)SO42-/SG as the catalyst,the optimum conditions for the synthesis of ethyl laurate by response surface is:the molar ratio of alcohol to acid is 5:1,the amount of catalyst is 4.6 wt%,reaction temperature is 383K,reaction time is 3.1h.Under these conditions,the yield of ethyl laurate was 95.1%.Under the optimum conditions,reaction order for synthesizing ethyl laurate is 1.39,the activation energy of reaction is 33.07 kJ/mol,the reaction kinetic equation is as r=-dCA/dt=6.334×102exp(-37.07/RT)CA1.39 follows:In the fifth chapter,using preparation of supported Br(?)nsted acid ionic liquid([DMBPSH]+-HSO4--/SG)as catalyst,investigated its catalytic activity.Research shows that supported Br(?)nsted acid ionic liquid have better catalytic activity.What's more,20%([DMBPSH]+-HSO4-/SG)showed the highest catalytic activity and the catalytic activity is improved when the catalyst is not loaded.The 20%([DMBPSH]+-HSO4-/SG)as catalyst to optimize the optimum conditions for the synthesis of ethyl laurate by response surface:the molar ratio of acid to alcohol is 5.05:1,the amount of catalyst is 3.5 wt%,temperature 383 K,reaction time is 2.5 h.Under these conditions,the yield of ethyl laurate was 97.2%.Under the optimized conditions,reaction order for synthesizing ethyl laurate is 1.34,the activation energy of reaction is 25.71 kJ/mol,r=_dCA/dt=88.698exp(-25.71/RT)CA1.34 the reaction kinetic equation is as follows:(?).