用混合二元酸制备混合酸二甲酯

Preparation of Mixed Dimethyl Esters from Mixed Dibasic Acids

以工业副产物混合二元酸(DBA)和甲醇为原料,用自制PW_(12)/SiO_2作催化剂制备混合酸二甲酯(DME),确定了最佳制箭条件:甲醇与DBA摩尔比为3.5,PW_(12)/SiO_2加入量(PW_(12)/SiO_2中PW_(12)占DBA的质量分数)为2%,反应时间为4.5 h,100 g DBA中甲苯加入量为50 mL。在此最佳条件下,DME收率为84.7%,所得DME为无色澄清液体,其中丁二酸二甲酯的质量分数为11.03%,戊二酸二甲酯的质量分数为13.88%,己二酸二甲酯的质节分数为73.79%。PW_(12)/SiO_2具有较好的稳定性和一定的重复使用性,PW_(12)/SiO_2重复使用5次时的DME收率仍大于70%。

Mixed dimethyl esters （DME） were prepared using by-product mixed dibasic acids （DBA） and methanol as raw materials and self-made PW12/SiO2 as catalyst. The optimum conditions are as follows： mole ratio of methanol to DBA 3.5, dosage of PW12/SiO2 （ mass ratio of PW12 to DBA） 2%, reaction time 4.5 h and adding 50 mL toluene into 100 g DBA. Under these conditions, the yield of DME is 84.7%. The product DME is a kind of colorless and pellucid liquid containing 11.03% dimethyl succinate, 13.88% dimethyl glutarate and 73.79% dimethyl adipate. When PW12/ SiO2 is recycled for 5 times, the yield of DME is still above 70%, which shows the good stability and reusability of PW12/SiO2.