Modified polylactic acid, preparation method and application thereof

A technology of polylactic acid and polylactic acid materials, applied in medical science, prosthesis, surgery, etc., can solve the problems of high energy consumption and inability to improve thermal stability, and achieve low consumption, simple operation process, and wide sources Effect

Inactive Publication Date: 2011-11-23
INST OF CHEM CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

On the one hand, the polymer additives selected by these schemes are not naturally formed and consume a lot of energy
On the other hand, although they all improved the impact resistance or toughness of PLA to a certain extent, they could not improve its thermal stability.

Method used

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  • Modified polylactic acid, preparation method and application thereof
  • Modified polylactic acid, preparation method and application thereof
  • Modified polylactic acid, preparation method and application thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0047] The impact of the content of embodiment 1, ENR-50 on the thermal stability of linear polylactic acid (abbreviated as PLA)

[0048] Mix PLA with different weights of ENR-50, dissolve in chloroform at 55°C, stir magnetically until it is completely dissolved, and cast a film. The mixture film was obtained by vacuum drying for 3 days under the condition of 90° C., and then annealed at 90° C. for 5 hours to obtain the modified polylactic acid provided by the present invention.

[0049] In this method, the weight ratios of PLA and ENR-50 used are: 99:1, 95:5 and 90:10, respectively. In addition, as a control, PLA and ENR-50 were also subjected to solution film formation in the same manner as above.

[0050] figure 1 (a) and (b) are the thermal degradation curves of PLA, ENR-50 and their mixtures with different weight ratios without annealing treatment and after annealing at 90℃ for 5h, respectively. pass figure 1 It can be seen that the introduction of ENR-50 can improve ...

Embodiment 2

[0051] Embodiment 2, the influence of the degree of epoxidation of additive ENR on the tensile properties of PLA

[0052] Blank experiment: Dissolve 1.2g PLA in chloroform at room temperature, stir magnetically until it is completely dissolved, and cast a film. After evaporating the solvent at room temperature, dry it in vacuum for 3 days at a vacuum degree of -0.1M Pa and a temperature of 30°C. The obtained film was annealed in an oven at 90°C for 5 hours to obtain a polylactic acid film, and its tensile properties are shown in Table 1. It can be seen from Table 1 that the elongation at break of polylactic acid is very low and the toughness is poor.

[0053] 90 parts by weight of PLA and 5 parts by weight of ENR with different epoxidation degrees (the epoxidation degrees of the ENR are respectively 25% and 50%, as shown in ENR-25 and ENR-50 in Table 1) were mixed, 55 Dissolve in chloroform at ℃, stir magnetically until completely dissolved, cast film, volatilize the solvent ...

Embodiment 3

[0055] Example 3, the influence of annealing temperature on the tensile properties and phase separation of PLA and its blended film with ENR-50

[0056] Blank experiment: Dissolve 1.2g PLA in chloroform at room temperature, stir magnetically until it is completely dissolved, and cast a film. After evaporating the solvent at room temperature, vacuum-dry it for 3 days at a vacuum degree of -0.1M Pa and a temperature of 30°C. The resulting film was annealed in an oven at different temperatures for 5 hours to obtain a polylactic acid film, and its tensile properties are shown in Table 1. It can be seen from Table 1 that as the annealing temperature increases, the tensile strength of PLA increases, but the toughness decreases significantly.

[0057] Mix 90 parts by weight of PLA and 10 parts by weight of ENR-50, dissolve in chloroform at 55°C, stir magnetically until completely dissolved, and then cast the film. Vacuum drying under the same conditions for 3 days to obtain a film o...

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Abstract

The invention discloses a modified polylactic acid (PLA), its preparation method and application. The preparation method of the modified polylactic acid comprises the steps of: reacting polylactic acid with epoxidized natural rubber (ENR) by a solution co-blending method or a melt extrusion method so as to obtain blends, annealing the blends, thus obtaining the modified polylactic acid. In the method, biodegradable polylactic acid is taken as the raw material, and the natural elastomer NR (natural rubber) or ENR is added through the solution co-blending method or melt extrusion method. By controlling the NR / ENR content and epoxidation degree, the melt extrusion temperature, the annealing temperature and annealing time, etc., the method adjusts the crystallinity, crosslinking degree and phase separation of PLA, so that the weakness of poor toughness of PLA is made up substantially, and the thermostability of PLA is improved. Thus, the processibility of PLA is improved. Characterized by simple process, easy operation and probable enforcement in production, the method provided in the invention provides a new choice for adjusting the properties of PLA.

Description

technical field [0001] The invention belongs to the technical field of polymer blending modification and relates to the modification of polymer materials, in particular to modified polylactic acid and its preparation method and application. Background technique [0002] Polylactic acid (PLA) is divided into linear polylactic acid, star-shaped polylactic acid and comb-shaped branched polylactic acid. Its monomer is lactic acid, and lactic acid is generally produced by fermentation of starch-containing crops such as wheat, rice, corn, and sugar beet. Therefore, PLA has a wide range of raw materials and is not affected by the depletion of petroleum resources. PLA can be naturally degraded into small molecules of lactic acid or water and carbon dioxide in the environment, without white pollution, which is beneficial to environmental protection. Therefore, PLA materials can form a complete material cycle from preparation, application to post-use treatment. It is an environmental...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08L67/04C08L15/00C08J5/18C08J3/24A61L27/18A61L31/06
Inventor 甘志华蒋妮
Owner INST OF CHEM CHINESE ACAD OF SCI
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