Use of stannous benzoate as catalyst

Abstract

The invention provides the usage of using the benzoic acid stannous as catalyst. The invention solves the problem that polymerization rate of current catalyst in lactic acid and glycolic acid is slow. The benzoic acid stannous is the catalyst used for preparing low-molecular polymer lactic acid with lactic acid dewatering; benzoic acid stannous is the catalyst used for preparing lactide with low-molecular polymer lactic acid cracking; benzoic acid stannous is the catalyst used for preparing polylactic acid with lactide polymerizing; benzoic acid stannous is the catalyst used for preparing low-molecular polymer glycolic acid with glycolic acid dewatering; benzoic acid stannous is the catalyst used for preparing glycolide with low-molecular polymer glycolic acid cracking; benzoic acid stannous is the catalyst used for preparing poly-glycollide with glycolide polymerizing. The benzoic acid stannous is the catalyst used for polymerizing glycolide, lactide and epsilon-caprolactone. Using the benzoic acid stannous is low content, high productivity, high product purity, low temperature and good repeatability.

Description

technical field [0001] The present invention relates to the purposes of stannous benzoate, relate in particular to the purposes of stannous benzoate in catalyst field. Background technique [0002] Catalyst refers to a substance that can change the reaction rate in a chemical reaction, but its quality and chemical composition do not change before and after the reaction; under the action of the catalyst, the reaction temperature, time and pressure can be greatly reduced. [0003] Under the action of a catalyst, lactic acid or glycolic acid is dehydrated to form an oligomer with a molecular weight of 2,000 to 10,000, and then directly cracked at high temperature and distilled under reduced pressure to obtain crude lactide or crude glycolide. Commonly used catalysts for dehydration oligomerization and pyrolysis of lactic acid or glycolic acid are: AlCl 3 , FeCl 3 , FeCl 2 , BF 3 , BBr 3 ,TiO 2 , TiCl 4 , TiBr 4 , SnSO 4 , SnBr 4 , stannous octoate, etc. The use of th...

AI Technical Summary

Problems solved by technology

[0005] The present invention aims at the shortcomings of the existing catalysts that the oligomerization rate of lactic acid and glycolic acid is slow, and the products are easily coked into blocks in the reactor during the cracking reaction process, the color of the obtained product is yellow, and the yield is relatively low, so it provides benzene Use of stannous formate as oligomerization and cracking catalyst