1-烷基-3-甲基咪唑硫酸氢盐催化油酸甲酯的研究

为寻找高活性催化剂，制备了5种甲基咪唑类硫酸氢盐离子液体（CnMIm]HSO4，n=0，2，4，6，8），测定了其酸性强度，研究了其酯化催化性能。结果表明：在这5种离子液体中，1-己基-3-甲基咪唑硫酸氢盐（C6MIm]HSO4）催化酯化反应效果最佳，其反应条件是：反应时间14h，反应温度为90℃，n（甲醇）；n（油酸）=2．5：1，催化剂用量为酸重的8％，油酸甲酯的产率可达91％以上．产物易于纯化，离子液体重复使用了6次仍显示出良好的催化效果．在温和．的实验条件下，C6MIm]HSO4对油酸的酯化反应显示出良好的催化活性．

Study on synthesis of methyl oleate catelyzed by 1-alkyl-3-methylimidazolium hydrosulfate

Five acidic ionic liquids with an hydrogen sulfate acid group were synthesized （Cn MIm] HSO4 ,n=0,2,4,6,8）. Their acidity was studied. Their application in esterification utilizing oleic acid and methanol was explored. The experimental results showed 1-hexyl-3-methyl-Imidulium hydrogen sulphate（C6MIm]HSO4） was the best catalyst of acidic ionic liquid in esterification. Under optimal esterification conditions ： n（methanol） ： n （ oleic acid） = 2. 5 ： 1, m （ oleic acid）：m〈C6MIm]HSO4） = 1 ： 0.08, temperature 90 ℃ and time 14 h, mass fraction of fatty acid methyl ester could reach more than 91%. The ionic liquids were stable and could be reused. Methyl oleate was separated from raw material easily; even if ionic liquid was reused beyond 6 times,the conversion of esterification did not decrease.