微波辐射下稀土固体超强酸催化合成蔗糖棕榈酸酯

Catalytic Synthesis of Sucrose Palmitic Acid Ester by Rare Earth Solid Super Acid under Microwave Irradiation

以蔗糖棕榈酸酯合成产率为目标函数,采用正交实验法分别研究了稀土固体超强酸催化剂的制备方法和微波辐射下催化合成蔗糖棕榈酸酯反应的最佳条件。结果表明,Nd3+-SO42-/ZrO2催化剂的最佳制备方法和条件为:通过ZrOCl2与NH3.H2O的沉淀反应制备无定型水合氧化锆;将合成的无定型水合氧化锆在2%的硫酸钕溶液中浸泡30min;浸积有钕的水合氧化锆沉淀经过滤、洗涤和干燥后在600℃下煅烧3h。而蔗糖与棕榈酸的酯交换反应条件为:酯糖比1∶1.2,微波辐射功率390W,反应时间15min,催化剂用量为原料的5%。在上述条件下,三次平行试验的平均产率达到68%,高于相同条件下以无水碳酸钾作催化剂时的合成产率。

The preparation procedure of rare earth solid super acid catalyst and interesterification reaction condition of palmitic acid ethyl ester with sucrose under microwave irradiation （SE） were investigated respectively as a function of yield of sucrose palmitic acid ester by using orthogonal experiment. It was found that the optimal procedures and conditions for the preparation of Nd3 ＋ - SO42 -/ZrO2 catalyst are as follow： preparing amorphous ZrO2·H2O through the precipitation reaction of ZrOCl2 with NH3· H2O solution;impregnating the ZrO2·H2O with 2% Nd2（SO4）3solution for 30min; calcining the as- impregnated ZrO2·HO at 600℃ for 3h after being filtrated, washed and dried. The optimal conditions for interesterilicafion reaction of palmitic acid with sucrose were found to be that the mass ratio of palmltic acid ethyl ester to sucrose is 1：1.2, the power of microwave is 390W with radiation time 15min, and the amount of catalyst 5%. With these optimized conditions, the average yield of SE reached up to 68%, which was higher than that with K2CO3 as catalyst under the similar synthesis condition.