酶法催化漆蜡合成漆蜡基异丙酯工艺研究

Lipase catalyzed synthesis of isopropyl ester from lacquer wax

以脂肪酶为催化剂,催化漆蜡与异丙醇进行酯交换反应合成漆蜡基异丙酯。首先采用傅里叶红外光谱对合成产物进行结构表征,然后采用单因素试验和正交试验对酯交换反应条件进行了优化,并对最佳条件下合成的漆蜡基异丙酯的组成进行了GC-MS分析。结果表明:在脂肪酶催化下,漆蜡可与异丙醇反应生成目标产物;Novozyme 435脂肪酶催化酯交换反应的最佳工艺条件为醇蜡比4∶1、脂肪酶加量10 g/L、反应温度55℃、反应时间36 h,在此条件下酯交换率为86. 7%,漆蜡基异丙酯的酸价(KOH)为3. 28 mg/g;漆蜡基异丙酯主要由棕榈酸异丙酯(73. 64%)、油酸异丙酯(19. 39%)、硬脂酸异丙酯(6. 15%)和亚油酸异丙酯(0. 82%)组成。

Synthesis of isopropyl ester from lacquer wax by transesterification with lipase catalyst was studied. The structure of the synthesized product was characterized by FT-IR. The transesterification conditions were optimized by single factor experiment and orthogonal experiment,and the compositions of the product synthesized under the optimal conditions were analyzed by GC-MS. The results showed that the isopropyl ester could be obtained by transesterification of lacquer wax and isopropanol with lipase as catalyst. The optimal conditions were obtained as follows: ratio of isopropanol to lacquer wax 4∶ 1,Novozymes 435 lipase dosage 10 g/L,reaction temperature 55 ℃,reaction time 36 h. Under these conditions,the transesterification rate was 86. 7%,and the acid value of isopropyl ester from lacquer wax was 3. 28 mgKOH/g. The product was mainly composed of isopropyl palmitate (73. 64%), isopropyl oleate (19. 39%),isopropyl stearate (6. 15%) and isopropyl linoleate (0. 82%).