丙二醇单甲醚乙酸酯的合成

使用 12 -磷钨酸为催化剂 ,以丙二醇单甲醚和乙酸为原料合成了丙二醇单甲醚乙酸酯。讨论了催化剂的用量、反应温度、反应时间、乙酸与丙二醇单甲醚的摩尔比等因素对反应的影响。最佳反应条件 :n(乙酸 ) /n(丙二醇单甲醚 ) =1 3 /1,磷钨酸催化剂用量为反应液质量的 0 4% ,带水剂环己烷用量为反应液质量的 2 5 % ,反应温度 110℃ ,反应时间 2 5h ,采用减压蒸馏分离提纯丙二醇单甲醚乙酸酯。用毛细管气相色谱法测定产品的含量 ,并通过沸程测定、元素分析等手段对产品进行了表征 ,产品的纯度 >99% ,收率 92 8%。

Synthesis of Propylene Glycol Monomethyl Ether Acetate

The paper introduced a process for preparing propylene glycol monomethyl ether acetate with acetic acid and 1,2-pro pyleneglycol-1-monomethyl ether as raw mate rials in the presence of 12-tungstophosphoric acid as catalyst.The influences on the yield of product of mole ratio of acetic acid to 1,2-propyleneglycol-1-monomethyl ether,reaction time,reaction temperature,and quantity of catalysts were i nvestigated.The optimum synthesis condit ions were:acetic acid /1,2-propyleneglyco l-1-monomethyl ether molar ratio,13∶1;catalyst/feedstock mass ratio,0004∶1;cyclohexane/feedstock mass ratio,025∶1;reaction time 25 h and reaction temperature 110 ℃.Propylene glycol monomethyl ether acetate was separated by distillation in vacuo.The composition of end-product was analyzed through capillary gas chromatography.Under the optimum conditions,the yield was 928% and purity over 99%.Through boiling range test and elementary analys is,the constitutional formula of the en d-product was proved to be propylene gly col monomethyl ether acetate.