Method used for producing poly L-lactic acid from L-lactic acid through oligomerization, melt phase polycondensation, and solid phase polycondensation

A technology of melt polycondensation and solid-state polycondensation, which is applied in the field of deep processing of lactic acid, can solve problems such as high cost, unsuitable for industrial application, and toxicity, and achieve mild reaction conditions, enhance product competitiveness, and reduce costs.

Active Publication Date: 2019-01-11
河南金丹乳酸科技股份有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The shortcoming of this method is: (1) lactide must be used as raw material, but in industrial production, lactic acid monomer is the cheapest raw material, and the cost of preparing lactic acid oligomerization mixture by lactide is higher; (2) using Solvents such as tetrahydrofuran are toxic and not suitable for industrial applications

Method used

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  • Method used for producing poly L-lactic acid from L-lactic acid through oligomerization, melt phase polycondensation, and solid phase polycondensation
  • Method used for producing poly L-lactic acid from L-lactic acid through oligomerization, melt phase polycondensation, and solid phase polycondensation
  • Method used for producing poly L-lactic acid from L-lactic acid through oligomerization, melt phase polycondensation, and solid phase polycondensation

Examples

Experimental program
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Effect test

Embodiment 1

[0108] A method utilizing L-lactic acid to produce poly-L-lactic acid through oligomerization, melt polycondensation and solid phase polycondensation, comprising the steps of:

[0109] (1) Raw material preparation: 45wt% L-lactic acid solution produced by the applicant, the optical purity of L-lactic acid is greater than or equal to 99.5%;

[0110] (2) Dehydration oligomerization to obtain L-lactic acid oligomers;

[0111] Add ethyl pyruvate to the L-lactic acid solution and stir to obtain a mixed solution, the volume ratio of ethyl pyruvate to the L-lactic acid solution is 1:1;

[0112] Simultaneously add cobalt oxide and two-cysteine ​​methyl ester vanadyl as catalyst in mixed solution according to the following steps:

[0113] During the initial reaction (0h): the mass ratio of cobalt oxide and di-cysteine ​​methyl ester vanadyl is 1:1.5, and the amount of cobalt oxide added during the initial reaction is 1 / 2 of the total amount of cobalt oxide added; The reaction tempera...

Embodiment 2

[0119] A method utilizing L-lactic acid to produce poly-L-lactic acid through oligomerization, melt polycondensation and solid phase polycondensation, comprising the steps of:

[0120] (1) Raw material preparation: 60wt% L-lactic acid solution produced by the applicant, the optical purity of L-lactic acid is greater than or equal to 99.5%;

[0121] (2) Dehydration oligomerization to obtain L-lactic acid oligomers;

[0122] Add ethyl pyruvate to L-lactic acid solution and stir to obtain a mixed solution, the volume ratio of ethyl pyruvate to L-lactic acid solution is 1:1; add cobalt oxide and di-cysteine ​​methyl ester to the mixed solution Vanadyl is used as a catalyst; the amount of cobalt oxide used is 0.04% of the mass of L-lactic acid, the amount of di-cysteine ​​methyl ester vanadyl is 0.08% of the mass of L-lactic acid, and the reaction is stirred for 3 hours at room temperature; The preparation method of vanadyl methyl ester is as follows: methyl cysteine ​​and vanadyl...

Embodiment 3

[0125] A method utilizing L-lactic acid to produce poly-L-lactic acid through oligomerization, melt polycondensation and solid phase polycondensation, comprising the steps of:

[0126] (1) Raw material preparation: 50wt% L-lactic acid solution produced by the applicant, the optical purity of L-lactic acid is greater than or equal to 99.5%;

[0127] (2) Dehydration oligomerization to obtain L-lactic acid oligomers;

[0128] Add ethyl pyruvate to the L-lactic acid solution and stir to obtain a mixed solution, the volume ratio of ethyl pyruvate to the L-lactic acid solution is 1:1;

[0129] Simultaneously add cobalt oxide and two-cysteine ​​methyl ester vanadyl as catalyst in mixed solution according to the following steps:

[0130] During the initial reaction (0h): the mass ratio of cobalt oxide and di-cysteine ​​methyl ester vanadyl is 1:1.5, and the amount of cobalt oxide added during the initial reaction is 1 / 2 of the total amount of cobalt oxide added; The reaction tempera...

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Abstract

The invention discloses a method used for producing poly L-lactic acid from L-lactic acid through oligomerization, melt phase polycondensation, and solid phase polycondensation. The method comprises following steps: 1, an L-lactic acid oligomer is prepared form L-lactic acid; 2, the L-lactic acid oligomer and a melt phase polycondensation catalyst are introduced into a melt phase polycondensationreaction vessel for melt phase polycondensation to prepare low molecular weight poly L-lactic acid, wherein the adding mass amount of the melt phase polycondensation catalyst is controlled to be 0.1 to 1% of that of the L-lactic acid oligomer; and 3, the obtained low molecular weight poly L-lactic acid is introduced into a solid phase polycondensation reaction vessel for solid phase polycondensation so as to obtain high molecular weight poly L-lactic acid. According to the method, cheap and easily available L-lactic acid obtained in practical industrial production is taken as a raw material toprepare the L-lactic acid oligomer with a narrow molecular weight distribution range, the reaction conditions are mile and are easy to control, the L-lactic acid oligomer yield is high, and it is suitable for industrialized production; and then the L-lactic acid oligomer is subjected to melt phase polycondensation, and solid phase polycondensation so as to obtain the L-lactic acid; the productioncost is reduced greatly; and product competitiveness is improved.

Description

technical field [0001] The invention relates to the technical field of deep processing of lactic acid. More specifically, it relates to a method for producing poly-L-lactic acid by utilizing L-lactic acid through oligomerization, melt polycondensation and solid-state polycondensation. Background technique [0002] Polylactic acid is a polymer with excellent performance, biocompatibility and biodegradability, mainly used in degradable packaging materials and drug microsphere carriers, anti-adhesive films, biological catheters, orthopedic fixtures, orthopedic surgical devices , artificial bone and other medical materials. [0003] In the process of preparing polylactic acid from monomeric lactic acid, lactic acid oligomers are first generated from monomeric lactic acid, and then polylactic acid is prepared by direct polycondensation of lactic acid oligomers; or lactide is prepared from lactic acid oligomers and then lactide Ring-opening polymerization produces polylactic aci...

Claims

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Application Information

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IPC IPC(8): C08G63/08C08G63/78C08G63/80
CPCC08G63/08C08G63/78C08G63/80
Inventor 崔耀军顾永华崔凯宁王浩邢晓霞葛大森李长天范小辉崔浩刘雁
Owner 河南金丹乳酸科技股份有限公司
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