Refining method of isosorbide

Abstract

The invention provides an isosorbide refining method, which comprises: S1, dissolving crude isosorbide in a first solvent to obtain a first solution, respectively treating the first solution through a cation exchange resin and an anion exchange resin to obtain a second solution, and distilling the second solution to obtain a primarily separated isosorbide solid; and S2, dissolving the primarily separated isosorbide solid in a second solvent, recrystallizing to obtain a solid matter and a filtrate, and separating and drying the solid matter to obtain refined isosorbide. The isosorbide product obtained by the refining method of the isosorbide is high in purity, and the method is simple to operate and wide in application range.

Description

technical field [0001] The invention relates to the field of preparation of isosorbide, in particular to a method for purifying isosorbide. Background technique [0002] Isosorbide, scientific name: 1,4:3,6-dianhydro-D-glucitol, is a biobased diol derived from starch or cellulose. Isosorbide has the advantages of green, non-toxic and chiral chemical structure, and has been widely used in food additives, cosmetics, pharmaceutical intermediates, high molecular polymers and other fields. Especially in the field of polymer production, isosorbide molecules are used to synthesize polycarbonates, polyesters, polyurethanes and polyamides due to their rigid molecular structure. [0003] At present, the domestic production capacity of isosorbide is relatively high, ranking in the forefront of the world; however, the application scope of isosorbide is relatively narrow, mainly concentrated in medicines, food additives, etc., and relatively few applications in polymer production. This...

AI Technical Summary

Problems solved by technology

However, the separation process in this production process has disadvantages such as high equipment requirements and high energy consumption, so it is rarely used in actual production

Patent document CN112574228A discloses a method of vacuum distillation and recrystallization, which not only consumes a lot of energy, but also has harsh operating conditions, and the purity of the obtained isosorbide is only 98%, which cannot meet the requirements of the polymerization industry. Requirements for the purity of isosorbide

[0005] In addition, the patent document CN108117560 A discloses a separation method for isosorbide, which uses steps such as decolorization, ion exchange, crystallization, and secondary crystallization. Although the purity of the isosorbide product obtained by this separation method is relatively high, if The isosorbide product is used as a raw material for polymer production, but the desired polymer product cannot be obtained

After in-depth research, the inventors speculate that this is because impurities such as metals and organic acids remain in the isosorbide product obtained by the separation method, which will limit the reactivity of the polymerization reaction, resulting in the application of the isosorbide product to The polymer obtained during the polymerization industry cannot reach the desired molecular weight