固体酸催化合成邻苯二甲酸二戊酯的研究

Synthesis of Dipentyl Phthalate Catalyzed by Solid Acid

以苯酐和正戊醇为原料,采用自制的固体酸SO42-/SiO2、SO42-/Fe2O3、SO42-/SnO2及SO42-/TiO2作为催化剂合成邻苯二甲酸二戊酯(DAP),分别考察固体酸催化剂的种类、固体酸催化剂的用量、醇酐比、反应时间等因素对合成DAP产率的影响。实验结果表明,其优化的工艺操作条件为:苯酐0.1 mol,固体酸催化剂SO42-/SiO2 1.7 g,醇酐比2.4∶1,带水剂二甲苯20 mL,反应时间3.5 h,其产品收率达91.3%以上。SO42-/SnO2作为该反应的催化剂具有催化活性高、寿命长、可多次重复使用、产物易纯化分离且产品色泽浅等优点,可望代替传统的浓硫酸作催化剂应用于DAP的合成。

Dipentyl phthalate was synthesized by esterification of n-butanol and phthalic anhydride with SO4^2-/SiO2, SO4^2-/Fe2O3, SO4^2-/SnO2 and SO4^2-/TiO2 as catalysts which had been prepared by our laboratory. The effects of types and amounts of solid acid catalysts, the ratio of butanol to phthalic anhydride, and the reaction time on the synthesis of dipentyl phthalate were studied. The results showed that the optimum conditions were 0.1 mol phthalic anhydride, 1.7 g SO4^2-/SnO2 catalyst, 20 mL xylene, butanol to phthalic anhydride in the ratio of 2.4 ： 1, reactive time of 3.5 h. The yield can reach above 91.3%. The catalyst of SO4^2-/SnO2 has the advantage of high catalytic activity, long life, and can be used repeatedly for many times. The products are light color and easy to be separated and purified. SO4^2-/ SnO2 can be expected to substitute concentrated sulfuric acid as catalyst in the field of synthesizing dipentyl phthalate.