NKC-9型正离子交换树脂催化合成混合二元酸二甲酯

Synthesis of mixed dibasic acid dimethyl esters catalyzed by strong acid cation resin NKC-9

以强酸型正离子交换树脂（牌号为NKC-9）为催化剂，混合二元酸和甲醇为原料，经预酯化和连续酯化反应制备混合二元酸二甲酯。结果表明，预酯化最佳反应条件为：NKC-9催化剂用量（以混合二元酸计，质量分数）8％，预酯化进料甲醇／混合二元酸（摩尔比）2．3：1．0，反应温度80—85℃，反应时间3．0ho连续酯化最佳反应条件为：NKC-9催化剂装填量35mL，预酯化产物进料量30-60mL／h，甲醇进料量100～210mL／h，连续酯化进料甲醇／剩余混合二元酸（摩尔比）大于50．0：1．0。在此条件下，混合二元酸预酯化转化率大于70％；剩余混合二元酸的酯化转化率及总转化率分别大于91．0％，97．0％。

Mixed dibasic acid dimethyl esters were pre- pared with strong acid cation resin NKC -9 as catalyst, mixed dibasic acids and methanol as raw materials by pre -esterifi- cation and continuous esterification reactions. The results showed that the optimum condition of pre - esterification was the mass fraction of catalyst in mixed dibasic acids 8%, methanol/mixed dibasic acids （ mole ratio） 2.3 ： 1.0, reac- tion temperature 80 - 85fC , reaction time 3.0 h. The opti- mum condition of continuous esterification was NKC - 9 cata- lyst 35 mL, pre -esterified product flow rate 30- 60 mL/h,methanol flow rate 100- 210 mL/ h, methanol/remaining mixed dibasic acids（ mole ratio） more than 50.0 ： 1.0. Under these conditions, the pre - esterification conversion of mixed dibasic acids was more than 70% ,and the esterification con- version of remaining mixed dibasic acids and the total conver- sion were more than 91.0% ,97.0% respectively.