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Method for preparing bio-degraded polymer particles by supercritical crystallization

A supercritical crystallization and biodegradation technology, applied in the production of bulk chemicals, etc., can solve the problems of purification and complexity of products that consume organic solvents, and achieve the effects of low cost, simple operation and no environmental pollution.

Inactive Publication Date: 2007-03-07
TONGJI UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

At present, in actual production, polylactic acid is still processed in an organic solvent medium, which consumes a large amount of organic solvent and complicates product purification.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0016] Introduce high-pressure carbon dioxide into the autoclave, and adjust the temperature and pressure to a steady state (40° C., 10 MPa). Polylactic acid (L-PLA) was dissolved in dichloromethane to form a 10 mg / ml organic solution. The dichloromethane solution of carbon dioxide and polylactic acid was sprayed into the autoclave at the same time, the flow rates were 20ml / min and 5ml / min, and the time was 5 minutes. The multiphase system was mixed and expanded in the autoclave at the same time. After the system was stabilized for about 5 minutes, fresh carbon dioxide was introduced into the autoclave and the high pressure (20Mpa) was maintained for 90 minutes to wash the residual organic solvent. Finally, it was slowly lowered to normal pressure, and the product was collected by opening the kettle. According to the scanning electron microscope (SEM) analysis, the average particle size of polylactic acid was 0.943 μm, which could be directly used to prepare injections, and co...

Embodiment 2

[0018] Introduce high-pressure carbon dioxide into the autoclave, and adjust the temperature and pressure to a steady state (40° C., 10 MPa). Polylactic acid (L-PLA) was dissolved in dichloromethane to form a 20 mg / ml organic solution. The dichloromethane solution of carbon dioxide and polylactic acid was sprayed into the autoclave at the same time, the flow rates were 20ml / min and 5ml / min, and the time was 5 minutes. The multiphase system was mixed and expanded in the autoclave at the same time. After the system was stabilized for about 5 minutes, fresh carbon dioxide was introduced into the autoclave and the high pressure (20Mpa) was maintained for 90 minutes to wash the residual organic solvent. Finally, the pressure was slowly lowered to normal pressure, and the product was collected by opening the kettle. According to the scanning electron microscope (SEM) analysis, the average particle size of polylactic acid was 1.773 μm, which could be directly used to prepare injectio...

Embodiment 3

[0020] Introduce high-pressure carbon dioxide into the autoclave, and adjust the temperature and pressure to a steady state (40° C., 10 MPa). Polylactic acid (L-PLA) was dissolved in dichloromethane to form a 30 mg / ml organic solution. The dichloromethane solution of carbon dioxide and polylactic acid was sprayed into the autoclave at the same time, the flow rates were 20ml / min and 5ml / min, and the time was 5 minutes. The multiphase system was mixed and expanded in the autoclave at the same time. After the system was stabilized for about 5 minutes, fresh carbon dioxide was introduced into the autoclave and the high pressure (20Mpa) was maintained for 90 minutes to wash the residual organic solvent. Finally, it was slowly lowered to normal pressure, and the product was collected by opening the kettle. According to the scanning electron microscope (SEM) analysis, the average particle size of polylactic acid was 2.050 μm, which could be directly used to prepare injections, and co...

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Abstract

The method for preparing biodegrable polymer particles by using supercritical crystallization technology includes the following steps: A. simultaneously pressing the organic solvent of supercritical carbon dioxide bio-enzyme polymer into the high-pressure reactor, mixing them at 20-50 deg.C and making expansion; B. setting and separating the said mixture; C. further introducing carbon dioxide, retaining high pressure for 90-100 min. and washing residual organic solvent. The carbon dioxide and organic solvent can be circularly used, and the obtained polymer particles can be extensively used for preparing slowly-released medicine.

Description

technical field [0001] The invention relates to a preparation method of polymer ultrafine particles, in particular to a method for preparing biodegradable polymer particles by supercritical crystallization. technical background [0002] Compared with the traditional process, the use of supercritical fluid to prepare ultrafine particles has the advantages of small grain size, narrow distribution and no solvent residue in the product, so it has a wider range of uses. Several different supercritical fluid deposition techniques have been proposed so far, mainly in the following two types, namely rapid expansion from supercritical solution (RESS) and gas anti-solvent recrystallization (GAS) , also known as gas stripping crystallization process). The entire process of RESS technology does not require organic solvents and does not require separation and treatment, and there is no pollution to the product. However, since the RESS technology requires that the processed substances m...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C08J3/14C08L67/00
CPCY02P20/54
Inventor 任杰宋金星滕新荣
Owner TONGJI UNIV