酸功能化离子液体磺烷基咪唑对甲苯磺酸盐催化合成松香甲酯的研究

Synthesis of Methyl Abietine Catalyzed by Acidic Functional Ionic Liquid Sulfonic Alkylimidazole p-Toluenesulfonate

制备、表征了酸功能化离子液体1-(3-磺酸)丙基-3-甲基咪唑对甲苯磺酸盐((HSO3-pm im)pTSA),并用于催化合成松香甲酯的反应研究,详细考察了甲醇用量、催化剂用量、反应温度、反应时间等因素对反应结果的影响,得到较佳的工艺条件:甲醇15 g,离子液体2.5 g,松香5 g,反应温度200℃,反应时间4 h。在该条件下,所得产物松香甲酯的酸值为17.4 mg/g;并对离子液体(HSO3-pm im)pTSA的重复使用性能进行了考察,分出的离子液体在不经处理直接重复使用5次时,所得产物松香甲酯的酸值为20.1 mg/g,具有较好的可重复使用性。

An acidic functional ionic liquid 1 - （ 3-sulfonic group ） propyl-3-methylimidazole p-toluenesulfonate [ （ HSO3-pmim ） pTSA] was synthesized, characterized and used to catalyze the esterification of rosin with methanol. The influences of reaction condition, such as amount of methanol and acidic functional ionic liquid, reaction time and reaciton temperature were examined. The optimum condition for esterification was obtained as follows：methanol 15 g, acidic ionic liquid 2.5 g, rosin 5 g, reaction temperature 200℃ and reaction time 4 h. Under the above condition, the acid value of methyl abietate was 17.4 mg/g, The recyclability of the ionic liquid was investigated, When the ionic liquid was repeatedly used for five times, the acid value of methyl abietate was still 20.1 mg/g. The catalyst for this synthesis has advantages of high yield, simple experimental operation and product isolation, and easy reusability of the catalyst, and it was expected to realize an clean and environmental friendly strategy for the production of methyl abietate.