Continuous preparation method of polyhydroxy acid with high molecular weight

A technology of polyhydroxy acid and high molecular weight, which is applied in the field of continuous preparation of polyhydroxy acid, can solve the problems of deep coloring of products, long polymerization reaction time, difficult removal of materials, etc., and achieve less coloring, excellent melt stability, strength and The effect of keeping the shape for a long time

Active Publication Date: 2013-09-18
CHANGZHOU UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This situation has led to a long polymerization reaction time, darker coloring of the product, difficulty in removing the material from the reaction system, and many other unfavorable situations for industrial production.

Method used

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  • Continuous preparation method of polyhydroxy acid with high molecular weight
  • Continuous preparation method of polyhydroxy acid with high molecular weight
  • Continuous preparation method of polyhydroxy acid with high molecular weight

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0067] Take 1000g of high-purity glycolide, add 50ppm of SnCl 2 2H 2 O, the two are mixed evenly with a pulverizer and then fed into the screw stirring reactor through the feeding funnel at a constant speed, and the feeding speed is kept consistent with the discharging speed. The reactor includes a total of 6 heating zones (e.g. Figure 5 As shown, that is, n=6), the temperature of each zone is set separately in advance. The reactor is set up as follows:

[0068] Feeding rate: 1kg / h; screw speed: 10rpm;

[0069] Reactor temperature: Zones 1 and 2 = 200°C; Zones 3 and 4 = 210°C; Zones 5 and 6 = 190°C;

[0070] The residence time is 10 minutes, the molecular weight average weight of the obtained polyglycolide is 180000, the molecular weight distribution range is 2.5; the yellowness index (YI) is 25.6; the melt viscosity is 500Pa·s.

Embodiment 2

[0072] Get the same glycolide 1000g of the purity in embodiment 1, add the SnCl of 500ppm 2 2H 2 O, the two are mixed evenly with a pulverizer and then fed into the screw stirring reactor through the feeding funnel at a constant speed, and the feeding speed is kept consistent with the discharging speed. The reactor is set up as follows:

[0073] Feeding rate: 1kg / h; screw speed: 30rpm;

[0074] Reactor temperature: Zones 1 and 2 = 210°C; Zones 3 and 4 = 220°C; Zones 5 and 6 = 190°C

[0075] The residence time is 3 minutes, the weight average molecular weight of the obtained polyglycolide is 250000, the molecular weight distribution range is 1.8; the yellowness index (YI) is 28.8; the melt viscosity is 620Pa·s.

Embodiment 3

[0077] Get the same glycolide 1000g of the purity in embodiment 1, add the SnCl of 2000ppm 2 2H 2 O, the two are mixed evenly with a pulverizer and then fed into the screw stirring reactor through the feeding funnel at a constant speed, and the feeding speed is kept consistent with the discharging speed. The reactor is set up as follows:

[0078] Feeding rate: 1kg / h; screw speed: 80rpm;

[0079]Reactor temperature: Zones 1 and 2 = 210°C; Zones 3 and 4 = 220°C; Zones 5 and 6 = 190°C

[0080] The residence time is 1.0 min, the weight average molecular weight of the obtained polyglycolide is 245000, the molecular weight distribution range is 2.0; the yellowness index (YI) is 47.1; the melt viscosity is 610Pa·s.

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Abstract

The invention relates to a continuous preparation method of polyhydroxy acid with high molecular weight and belongs to the technical field of environmentally-friendly high molecular materials. A one-segment / multi-segment temperature controllable screw reactor is used, organic / inorganic lewis acid is used as a catalyst, certain temperature, catalyst dose and screw rotation speed are controlled, a cyclic ester monomer and the catalyst are continuously subjected to polymerization, and a product is fast obtained by means of continuous discharge. The chromaticity of the polyhydroxy acid is regulated and the stability of the polyhydroxy acid is improved by directly adding an antioxidant and a blocking agent at the middle-rear segment of the reactor. The prepared polyhydroxy acid has the advantages of high molecular weight and low chromatic value.

Description

technical field [0001] The invention relates to a method for continuously preparing polyhydroxy acid, which belongs to the technical field of environment-friendly polymer materials. technical background [0002] Traditional polymer materials generally come from non-renewable petroleum resources and are difficult to degrade. Although it plays an irreplaceable role in the process of social and economic development, it faces the problems of white pollution and energy shortage. [0003] At present, as a kind of degradable and environmentally friendly polymer materials, polyhydroxy acid has the advantages of easy processing, convenient recycling, non-toxic and harmless, and less pollution. Among them, polyglycolic acid and polylactide have good gas barrier properties, excellent mechanical properties, good biocompatibility and excellent degradability, and are widely used in medical absorbable surgical sutures, drug slow and controlled release, High value-added products that simu...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08G63/08C08G63/80C08G63/85C08G63/86C08G63/83
CPCC08G63/06C08G63/08C08G63/83C08G63/85C08G63/912
Inventor 陈群崔爱军何明阳周维友陈圣春
Owner CHANGZHOU UNIV
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