杂多酸对二甘醇脱水环化反应的催化作用

研究了杂多酸对二甘醇脱水环化的催化作用。结果表明，磷钨酸，硅钨酸，硅钼酸具有较高的催化活性，而磷钼酸的催化活性较低。采用ＴＧ，ＩＲ，ＧＣ－ＭＳ，电导等测试技术，对正丁胺酸性，杂多阴离子碱度，还原特性的测定及对产物结构的分析。

Cyclization of Diethylene Glycol on Heteropoly Acid

Catalytic performance of HPAS (heteropolyacids) such as 12- tungstosphosphoric acid (PW12), 12- tungstosilicic acid (SiW12), 12-molybdophosphoric acid (PMo12), and 12-molybdosilicic acid (SiMo12) were studied for the etherification of diethylene glycol.It has been shown that PW12 SiW12, and SiMo12, have higher activities for this reaction. The results of GC, GC-MS, IR, n -butylamine titrition, the mensuration for the molar conductivity of solutions, and the determination of basicity and susceptibility to reduction of the heteropoly anions, indicate that if the acidity of HPA is too strong and the heteropoly anions are too soft, 1, 4-dioxane will isomerize to 2-methy1-1, 3-dioxolane.