摘要
采用两步法合成了4种不同阳离子的功能化离子液体:1-甲基-3-(3-磺丙基)咪唑硫酸氢盐([C_3SO_3Hmim]HSO_4)、1-乙基-3-(3-磺丙基)咪唑硫酸氢盐([C_3SO_3Emim]HSO_4)、1-丙基-3-(3-磺丙基)咪唑硫酸氢盐([C_3SO_3-Pmim]HSO_4)、1-丁基-3-(3-磺丙基)咪唑硫酸氢盐([C_3SO_3Bmim]HSO_4)。通过FTIR、1H NMR和TG分析了离子液体的结构和热稳定性。并将其应用于催化丁二酸酐和乙醇的酯化反应中,考察了4种离子液体的催化活性。结果表明,离子液体[C_3SO_3Bmim]HSO_4的催化效果较好,在n(丁二酸酐)∶n(乙醇)=1∶2.5,催化剂用量9%,环己烷用量35%,反应温度90℃的条件下反应5 h后,丁二酸二乙酯的收率可达92.28%,且离子液体催化剂循环使用8次后,仍具有较高的催化活性。与传统工艺相比,离子液体催化剂具有用量少、反应条件温和、无副反应、收率高和可循环使用等优点,具有替代传统浓硫酸催化醇酸酯化反应的潜力。
Four kinds of functional ionic liquids,1-methyl-3-（ 3-sulfopropyl） imidazolium hydrogen sulfate（ [C_3SO_3Hmim]HSO_4）,1-ethyl-3-（ 3-sulfopropyl） imidazolium hydrogen sulfate（ [C_3SO_3Emim]HSO_4）,1-propyl-3-（ 3-sulfopropyl） imidazolium hydrogen sulfate（ [C_3SO_3Pmim]HSO_4）,1-butyl-3-（ 3-sulfopropyl） imidazolium hydrogen sulfate（ [C_3SO_3Bmim]HSO_4）,were designed and synthesized. The properties of samples were characterized by FTIR,1H NMR and TG. The catalytic activities of the functional ionic liquid were investigated by the esterification of succinic anhydride with ethanol. The results showed that under the optimized conditions n（ succinic anhydride） ∶ n（ ethanol） = 1 ∶ 2. 5,catalyst dosage 9%,water carrying agent dosage 35%,reaction temperature 90 ℃ and reaction time 5 h,the yield of diethyl succinate was up to 92. 28%. The ionic liquids dried in vacuum till remained high activity after reused for 8times. Moreover,compared to conventional industrial catalysts,ionic liquid catalyst needed less,and had the superiorities of less by-product,mild reaction conditions,high yield and the catalyst could be recycled,and has the potential of replacing the traditional sulfuric acid in catalytic esterification reaction.
出处
《应用化工》
CAS
CSCD
北大核心
2016年第5期801-805,共5页
Applied Chemical Industry
基金
国家自然科学基金资助项目(20576026
21106032)
