离子液体N-甲基咪唑对甲苯磺酸盐催化剂的制备及应用

Preparation of an Ionic Liquid [Hmim]TsO and Its Use as Catalyst for Esterification

采用一步法制备Brφnsted酸性离子液体N-甲基咪唑对甲苯磺酸盐催化剂([Hmim]TsO),并对其进行了红外光谱、拉曼光谱等表征。将其应用于醋酸和正丁醇的酯化反应,详细考察了离子液体用量、反应时间、醇酸物料比、反应温度等因素对酯化反应的影响,并确定了较佳反应条件为:温度95～98℃,n(丁醇)∶n(醋酸)=1.2∶1,离子液体用量为反应物总质量的20.0%,反应时间6h,酯化率可达到85.0%。同时,[Hmim]TsO离子液体循环使用6次后,酯化率仍可达到78.2%。

A novel ionic liquid [Hmim]TsO catalyst was prepared with one step method. The catalyst was characterized by FT-IR, FTRaman. Ionic liquid was used in esterification reaction of acetic acid and n-butyl alcohol. [Hmim]TsO is a good substitute of conventional catalyst system as catalyst. The influencing factors of reaction were measured including amount of ionic liquids, reaction time, mole ratio of n-butanol to acetic acid, reaction temperature. The optimization conditions were： reaction temperature 95-98 ℃, mole ratio of n-butanol to acetic acid 1.2：1, ionic liquids mass fraction 20.0% in reaction medium, and the reaction time 6 h. Under the optimization conditions, the yield of n-butyl acetate is 85.0%. The ionic liquid could be reused, and the yield still reaches 78.2% after reused 6 times.