Prepn of dissolved liquid crystal of chitosan grafted polylactic acid

A technology of lyotropic liquid crystals and chitosan, which is applied in the field of preparation of chitosan-grafted polylactic acid lyotropic liquid crystals, can solve problems such as application limitations, poor hydrophilicity, and unclear physiological effects of polyvinyl alcohol, and achieve solubility Improved effect

Inactive Publication Date: 2003-01-01
SHANGHAI JIAO TONG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, due to the poor hydrophilicity of its surface, the degradation time in the human body is long, so that it causes adverse reactions in the body
For a long time, people have used other hydrophilic and water-soluble materials to improve the surface hydrophilic properties of polylactic acid, such as

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0012] Implementation of chitosan with 50% deacetylation degree and lactide molar ratio of 1:1.

[0013] The chitosan with a deacetylation degree of 50% was dried in a vacuum oven for 48 hours to remove the adsorbed water on its surface. Weigh 0.05 mol of chitosan and add it into the reactor, degas under vacuum for 1 hour, add 40 ml of dried toluene as a dispersant, and prepare it into a 1.25 mol toluene dispersion. Weigh 0.05 mol of triethylaluminum to prepare a 15% toluene solution. Add the triethylaluminum solution dropwise to the chitosan toluene dispersion at room temperature, and react for another 1 hour when no gas is generated. Add 0.05 mol of lactide degassed by vacuum for 1 hour, then place the reactor in an oil bath preheated to 70°C, react for more than 20 hours, pour the reaction solution into ethanol, make it fully precipitate, filter and dry After being dissolved in water, its cholesteric solution liquid crystal behavior can be observed under a polarizing micr...

Embodiment 2

[0015] The implementation of chitosan and lactide with a degree of deacetylation of 94% at a ratio of 1:1.

[0016] The chitosan with a deacetylation degree of 94% was dried in a vacuum oven for 48 hours to remove the adsorbed water on its surface. Weigh 0.05mol chitosan and add it into the reactor, and degas it under vacuum for 1 hour. Add 60ml of dried toluene for dispersion to prepare a 0.83 mole toluene dispersion. Weigh 0.05 mol of triethylaluminum to prepare a 15% toluene solution. Add the triethylaluminum solution dropwise to the chitosan toluene dispersion at room temperature, and react for another 1 hour when no gas is produced. Add 0.05 mol of lactide degassed by vacuum for 1 hour, then place the reactor in an oil bath preheated to 70°C, react for more than 20 hours, pour the reaction solution into ethanol, make it fully precipitate, filter and dry After being dissolved in trifluoroacetic acid, when the solution concentration is greater than 1%, its cholesteric so...

Embodiment 3

[0018] Acetyl degree 94% chitosan and lactide 1:60 implementation. The chitosan with a deacetylation degree of 94% was dried in a vacuum oven for 48 hours to remove the adsorbed water on its surface. Weigh 0.005mol chitosan and add it into the reactor, and degas it under vacuum for 1 hour. Add 100ml of dried toluene as a dispersant to prepare a 0.05 mole toluene dispersion. Weigh 0.005 mol of triethylaluminum to prepare a 15% toluene solution. Add the triethylaluminum solution dropwise to the chitosan toluene dispersion at room temperature, and react for another 1 hour when no gas is produced. Add 0.3 mol of lactide that has been vacuum degassed for 1 hour, then place the reactor in an oil bath preheated to 70°C, react for more than 20 hours, pour the reaction solution into ethanol, make it fully precipitate, filter and dry After being dissolved in dichloroacetic acid, its cholesteric solution liquid crystal behavior can be observed under a polarizing microscope when the so...

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PUM

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Abstract

The preparation of dissolved liquid crystal of chitosan grafted polylactic acid includes vacuum deairing of chitosan for 1 hr, charging nitrogen, adding toluene as dispersant, dripping toluene solution of aluminium ethide as catalyst in 1-3 molar times of chitosan, ring opening polymerization of lactide inside solution to produce grafted copolymer of chitosan and polylactic acid. The copolymer is dissolved in trifluoro acetic acid, acetic acid, dichluoro acetic acid or water, and when the solution concentration is greater than 1%, the liquid crystal behavior may be observed in polarizing microscope. The grafted copolymer of the present invention has special performance, and may be used as interface coupling agent for polymer blend of chitin, chitosan and polylactic acid as well as medicine delayed releasing material and other human body implanting biological material and various biological fibrous material.

Description

Technical field: [0001] The invention relates to a method for preparing chitosan-grafted polylactic acid lyotropic liquid crystals. The prepared material has a liquid crystal state, and its processing range can be expanded. For example, it is possible to obtain high-strength fibers by spinning liquid crystal solutions in a solution state. As a reinforcing fiber for surgical sutures and other biocomposites. Background technique: [0002] Chitin is the second largest naturally synthesized polymer material next to cellulose, and the annual output of this material by biosynthesis is as high as nearly one billion tons. However, due to the hydrogen bonds in the chitin molecule, it has neither a specific melting point nor is it soluble in common solvents, which greatly limits its usability. Chitosan is the deacetylation product of chitin. Like chitin, it has unique biological functions such as anti-inflammation, hemostasis, and promotion of cell regeneration. It may find its wide ...

Claims

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Application Information

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IPC IPC(8): C08B37/08C08G81/00
Inventor 刘预田丰陈刚胡克鳌
Owner SHANGHAI JIAO TONG UNIV
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