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Novel multi-block PLA (polylactic acid) and synthesis method thereof

A synthesis method and multi-block technology, applied in the field of new multi-block PLA and its synthesis, can solve the problems of large product batch difference, chain extender affecting application, single block type, etc., and achieve low distribution coefficient and molecular weight. The effect of good controllability and high reaction conversion rate

Inactive Publication Date: 2017-10-10
SICHUAN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] At present, multi-block polylactic acid is mainly prepared by the method of chain extension. The block type is single (the molecular weight of a single block is not variable), and the steps are cumbersome, and the energy consumption is high, resulting in large differences in product batches and residual chain extension. Agents affect its application in the biological field

Method used

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  • Novel multi-block PLA (polylactic acid) and synthesis method thereof
  • Novel multi-block PLA (polylactic acid) and synthesis method thereof
  • Novel multi-block PLA (polylactic acid) and synthesis method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0033] Example 1. Preparation of PLLA.

[0034] (1) Reaction steps

[0035] 1. Prepare monomer LLA, benzyl alcohol, DCM, catalyst DBU, reaction flask, etc.;

[0036] 2. Weigh benzyl alcohol (0.0426g, 0.3944mmol) and LLA (1.1429g, 7.9368mmol) respectively in a 25mL eggplant-shaped reaction flask and stir to dissolve with 11.6mL DCM;

[0037] 3. Weigh the catalyst DBU (0.0106g / 11μL) and quickly add it to the reaction bottle containing the initiator and the monomer to react, take out a small amount of product at 15, 30, and 45min, and then vacuum-dry it for H'NMR detection;

[0038] After 4.1 h, a small amount of benzoic acid was added to terminate the reaction, followed by vacuum drying and NMR detection.

[0039] (2) The detection and data analysis results are as follows: figure 1 shown. From figure 1 The results in Table 1 can be obtained.

[0040] Table 1 H’NMR LLA monomer conversion data summary table

[0041]

[0042] (3) Summary

[0043] The reproducibility of t...

specific Embodiment 2

[0044] Specific Example 2. Preparation of PLLA-b-PDLA.

[0045] (1) Reaction steps

[0046] 1. Prepare monomer LLA, DLA, benzyl alcohol, DCM, catalyst DBU, reaction flask, etc.;

[0047] 2. Weigh benzyl alcohol (0.0197g, 0.1824mmol) and LLA (0.5834g, 4.0514mmol) respectively in a 25mL eggplant-shaped reaction bottle and stir to dissolve with 6.2mL DCM;

[0048]3. Weigh the catalyst DBU (0.0056g / 6μL) and quickly add it to the reaction bottle containing the initiator and the monomer to react. After 20min of reaction, take out 1mL product for nuclear magnetic detection, and weigh DLA (0.4471g / 3.1049mmol ) was dissolved in 5.2mL DCM and then added to the system to continue the reaction. A small amount of product was taken out at 0.5, 1, and 1.5h respectively and then vacuum-dried for H'NMR detection;

[0049] After 4.2 hours, a small amount of benzoic acid was added to terminate the reaction, followed by vacuum drying and NMR detection.

[0050] (2) Detection and data analysis ...

specific Embodiment 3

[0057] Specific Example 3. Preparation of PLLA-b-PDLA-b-PLLA-b-PDLA.

[0058] (1) Reaction steps

[0059] 1. Prepare monomer LLA, DLA, benzyl alcohol, DCM, catalyst DBU, reaction flask, etc.;

[0060] 2. Weigh benzyl alcohol (0.0234g, 0.2167mmol) and LLA (0.5407g, 3.7549mmol) respectively in a 25mL eggplant-shaped reaction bottle and stir to dissolve with 6.2mDCM;

[0061] 3. Weigh the catalyst DBU (0.0056g / 6μL) and quickly add it to the reaction bottle containing the initiator and the monomer for reaction. After 15 minutes of reaction, take out 1mL product for nuclear magnetic detection, and weigh DLA (0.4448g / 3.0889mmol ) was dissolved in 5.2mL DCM and added to the system to continue the reaction, and 0.5mL of the product was taken out at 0.5 and 1h respectively and then vacuum-dried for H'NMR detection;

[0062] 4. After the second stage of reaction for 1h, weigh LLA (0.3647g, 2.5326mmol) and dissolve it with 4.2mL of DCM and add it to the reaction system to continue the ...

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Abstract

The invention belongs to the field of chemical synthesis and particularly relates to novel multi-block PLA (polylactic acid) and a synthesis method thereof. A polymer of the novel multi-block PLA contains at least one PLLA block and at least one PDLA block which are staggered, the molecular weight of the polymer is 72 Da-100 KDa, and the molecular weight of each PLLA block and each PDLA block is 72 Da-100 KDa. According to the novel multi-block PLA and the synthesis method thereof, lactide ring opening polymerization is initiated with an alcoholic hydroxyl group used as an initiator and small organic molecules used as a catalyst to form PLA, and the block PLA with different configurations and variable molecular weight is prepared by changing the configuration and lactide and the molar ratio. The PLA prepared with the method is high in reaction conversion rate, short in time, good in molecular weight controllability, flexible in block controllability and low in distribution coefficient. The excellent polymerization method provides a novel and feasible method for preparing PLA with diversified configurations and structures, controllable molecular weight and low distribution coefficient.

Description

technical field [0001] The invention belongs to the field of chemical synthesis, in particular to a novel multi-block PLA and a synthesis method thereof. Background technique [0002] Polylactic acid (PLA) is a degradable polyester with excellent mechanical properties due to its high crystallinity. The synthesis of polylactic acid is mainly obtained by direct polycondensation of lactic acid monomer or ring-opening polymerization of lactide. [0003] The direct polycondensation method is to directly dehydrate the lactic acid molecules under certain temperature conditions to form a polymer with a certain molecular weight. This method is simple, but it consumes a lot of energy, and the molecular weight of the obtained polymer is difficult to control, and the distribution coefficient is relatively large. The direct polycondensation reaction is a reversible equilibrium reaction. At the end of the reaction, as the viscosity of the system increases, it is difficult to continue th...

Claims

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Application Information

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IPC IPC(8): C08G63/08C08G63/87
CPCC08G63/08C08G63/823
Inventor 曹俊成富荣苏婷李莉何斌
Owner SICHUAN UNIV