Method for preparing polyester containing isosorbide

Abstract

The invention discloses a method for preparing a polyester containing isosorbide, comprising the following steps of: carrying out dehydration reaction on raw materials including isosorbide and dicarboxylic acid which have equal molar weight under the action of a polycondensation catalyst and a water-carrying agent under normal pressure, and carrying out a vacuum polycondensation to prepare the polyester containing isosorbide, wherein the water-carrying agent comprises one or more of the methyl isopropyl ketone, ethyl isopropyl ketone, methyl isobutyl ketone, diisopropyl ketone and diisobutyl ketone. According to the method, an appropriate amount of water-carrying agent is added during the direct esterification reaction of the isosorbide and the binary acid, thus the reaction temperature is decreased greatly, and the molecular weight and the polymerization efficiency of the polyester are improved.

Description

technical field [0001] The invention relates to a preparation method of isosorbide-containing polyester, in particular to a preparation method of isosorbide-containing polyester with relatively high molecular weight. Background technique [0002] As the dehydration product of sorbitol, isosorbide can be easily prepared from renewable resources such as D-glucose by hydrogenation and then acid-catalyzed dehydration. feature. Polyester containing isosorbide has higher viscosity and glass transition temperature, better processability, spinnability and dyeability, and further enhanced impact resistance and mechanical strength. Therefore, the polyester can be widely used in products such as bottles, heat-filled containers, films, thick plates, fibers, wires and optical products. [0003] US6291629B1 and Okada M etc. in "J Appl Polym Sci" Volume 7 1 P57-70 "Biodegradable polymers from 1,4:3,6-dianhydrod-glucitol (isosorbide) and its related compounds" and Storbeck R et al. in "Po...

AI Technical Summary

Problems solved by technology

Esterification polymerization after activation of isosorbide or dibasic acid increases the preparation steps and increases the cost. In addition, the activation step of the monomer is difficult to control; isosorbide polyester directly participates in the esterification reaction, because isosorbide Structural features, often require a higher esterification temperature, not only the esterification effect is poor but also need to add diols other than isosorbide, reducing the content of isosorbide in polyester

As we all know, adding an appropriate amount of water-carrying agent in the esterification reaction of alcohol and acid will improve the esterification effect, but in the esterification reaction in which isosorbide directly participates, because the reaction system and raw materials are different from ordinary esterification reactions, it is necessary to choose It is not easy to find a suitable water-carrying agent, which is why the water-carrying agent is rarely used when isosorbide directly participates in the esterification reaction in the prior art