对甲苯磺酸催化合成硬脂酸甲酯

Synthesis of Methyl Stearate Catalyzed by p-Toluene Sulfonic Acid

以对甲苯磺酸催化硬脂酸和甲醇的酯化反应,合成了硬脂酸甲酯,研究结果表明,对甲苯磺酸对酯化反应具有较高的催化活性。考察了反应时间、酸醇摩尔比、催化剂用量对酯化反应的影响。当硬脂酸与甲醇的摩尔比为1∶3.5,对甲苯磺酸用量为硬脂酸质量的1.2%,于回流温度反应4 h,硬脂酸的转化率大于98.5%,产品酸值小于3.0 mg KOH/g。

Methyl stearate was synthesized by esterification of stearic acid with methyl alcohol using p-toluene sulfonic acid as a catalyst.The results indicated that p-toluene sulfonic acid possessed high catalytic activity for the esterification reaction.The synthetic conditions were optimized,including the reaction time,the molar ratio of stearic acid to methyl alcohol and the amount of p-toluene sulfonic acid used.The optimal reaction conditions were as follows： n（stearic acid）∶n（methyl alcohol）=1∶3.5,2.5% p-toluene sulfonic acid（based on the weight of stearic acid）,refluxing for 4 h.The conversion of stearic acid was greater than 98.5%,the acid value of the product was smaller than 3.0 mg KOH/g.