SO_4~(2-)/TiO_2-SnO_2-Al_2O_3催化合成衣康酸二异辛酯的研究

研究了固体超强酸SO42-/TiO2-SnO2-Al2O3催化衣康酸与异辛醇合成衣康酸二异辛酯的酯化反应,甲苯作为带水剂,考察了催化剂种类,确定以SO24-/TiO2-SnO2-Al2O3为催化剂。随后考察反应物配比、催化剂用量、反应时间等因素对酯化反应的影响,确定了最佳工艺条件为n(衣康酸):n(异辛醇)=1:3,催化剂用量4.5%(质量分数),反应时间2h。在该条件下,衣康酸转化率达到98.9%,产物衣康酸二异辛酯的收率为96.2%。并对SO24-/TiO2-SnO2-Al2O3的重复使用性能进行考察,结果表明,与SO24-/TiO2相比,SO42-/TiO2-SnO2-Al2O3在重复使用5次后仍具有较高的催化活性,衣康酸转化率和衣康酸二异辛酯收率为分别为98.2%和95.7%,说明载体中添加Sn和Al对于增加固体超强酸的寿命起了主要作用。

Study on synthesis of diisooctyl itaconate with SO2-4/TiO2-SnO2-Al2O3

Esterification for the synthesis of diisooctyl itaconate using itaconic acid and isooctyl alcohol as materials, SO4^2-/TiO2-SnO2-Al2O3 solid superacid as catalyst and toluene as water carrying agent, was studied. Characteristics of catalyst were survied and SO4^2-/TiO2-SnO2-Al2O3 was selected as catalyst. Effects of amount - of - substance ratio of reactants, amount of catalyst, and reaction time on reaction results were investigated. Optimum conditions were obtained as follows ： n （ itaconic acid） ： n （ isooctyl alcohol ） = 1 ： 3, catalyst amount was 4.5% （ the total mass of reactants ）, reaction time was 2 h. Under these conditions, conversion of itaconic acid and yield of diisooctyl itaconate were 98.9% and 96.2%, respectively. Reusability of SO4^2-/TiO2-SnO2-Al2O3 was investigated and compared with SO4^2-/TiO2, it still had high catalytic activity after using 5 times,and conversion of itaconic acid and yield of diisooctyl itaconate were 98.2% and 95.7%, respectively. Experimental results showed that adding Sn and Al was important to extend the life of SO4^2-/TiO2-SnO2-Al2O3.