Method for preparing high-strength chitosan hydrogel through thermal gelation-nearly neutral water bath

A thermal gelation and near-neutral technology, which is applied in pharmaceutical formulations, medical preparations of non-active ingredients, pharmaceutical sciences, etc., can solve the problems affecting the mechanical properties of products, the increase of molecular weight polydispersity, and the decrease of molecular weight. Achieve the effects of fast diffusion removal, uniform direction properties, and avoid swelling and softening

Inactive Publication Date: 2014-01-01
ZHEJIANG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

When the acidic solution of chitosan is placed, an acid-catalyzed hydrolysis reaction occurs, and its main chain is continuously broken due to hydrolysis, resulting in a decrease in molecular weight and an increase in molecular weight polydispersity, which in turn seriously affects the mechanical properties and other qualities of the product.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] 1) Take chitosan 0.5g, lithium hydroxide 4.0g, potassium hydroxide 4.0g, water 91.5g. The above components were mixed and swelled for 3 hours, the swelling solution was frozen at -60° C. for 1 hour, and then thawed at room temperature with stirring to obtain a chitosan alkaline aqueous solution system.

[0018] 2) Filtrating, centrifuging, and defoaming the chitosan alkaline aqueous solution prepared in step 1) to obtain a transparent non-foaming chitosan alkaline aqueous solution.

[0019] 3) The non-foaming chitosan alkaline aqueous solution prepared in step 2) is injected into a gel preparation mold, and put into an oven for thermal gelation. The oven temperature is 40°C, the thermal gelation time is 120min, and the gel is released from the mold.

[0020] 4) Soak the released chitosan alkaline gel in water to remove the alkaline hydroxide. Using phenolphthalein as an indicator, with the diffusion of alkaline hydroxide inside the gel, add H with a mass concentration...

Embodiment 2

[0022] 1) Take 1.0g of chitosan, 6.0g of lithium hydroxide, 4.0g of potassium hydroxide, and 89g of water. The above components were mixed and swelled for 1 hour, the swelling solution was frozen at -20° C. for 1 hour, and then thawed at room temperature with stirring to obtain a chitosan alkaline aqueous solution system.

[0023] 2) Filtrating, centrifuging, and defoaming the chitosan alkaline aqueous solution prepared in step 1) to obtain a transparent non-foaming chitosan alkaline aqueous solution.

[0024] 3) The non-foaming chitosan alkaline aqueous solution prepared in step 2) is injected into a gel preparation mold, and put into an oven for thermal gelation. The oven temperature is 40°C, the thermal gelation time is 30min, and the gel is released from the mold.

[0025] 4) Soak the released chitosan alkaline gel in water to remove the alkaline hydroxide. With bromothymol blue as indicator, with the diffusion of alkaline hydroxide inside the gel, add H2O with a mass co...

Embodiment 3

[0027] 1) Take 8.0g chitosan, 6.0g lithium hydroxide, 8.0g potassium hydroxide, and 78g water. The above components were mixed and swelled for 2 hours, the swelling solution was frozen at -20°C for 4 hours, and then thawed at room temperature with stirring to obtain a chitosan alkaline aqueous solution system.

[0028] 2) Filtrating, centrifuging, and defoaming the chitosan alkaline aqueous solution prepared in step 1) to obtain a transparent non-foaming chitosan alkaline aqueous solution.

[0029] 3) The non-foaming chitosan alkaline aqueous solution prepared in step 2) is injected into a gel preparation mold, and put into an oven for thermal gelation. The temperature of the oven is 80° C., the thermal gelation time is 30 minutes, and the gel is released from the mold.

[0030] 4) Soak the released chitosan alkaline gel in water to remove the alkaline hydroxide. Using phenolphthalein as an indicator, with the diffusion of alkaline hydroxide inside the gel, add H at a mass c...

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Abstract

The invention discloses a method for preparing high-strength chitosan hydrogel through thermal gelation-nearly neutral water bath. The method comprises the following steps: preparing 0.5-8.0wt% of chitosan, 4.0-6.0wt% of lithium hydroxide, 4.0-8.0wt% of potassium hydroxide and water, mixing and dissolving the components, freezing, thawing, filtering, centrifuging and defoaming the mixture, injecting the mixture into a gel preparation mould to carry out thermal gelation, and then, demolding and soaking in water, removing the alkaline hydroxide in nearly neutral water bath by utilizing phenolphthalein or bromothymol blue as an indicator, and removing the neutral salt and the indicator by using deionized water, thus obtaining the high-strength chitosan hydrogel.

Description

technical field [0001] The invention relates to a preparation method of chitosan hydrogel, in particular to a method for preparing high-strength chitosan hydrogel by thermal gelation-near neutral water bath. Background technique [0002] Chitosan is the second largest type of natural organic polymer material except cellulose, and it is also the only natural alkaline polysaccharide. Chitosan has many excellent properties: biocompatibility, antibacterial, low immunogenicity, low toxicity, biodegradability, etc. Many excellent properties make chitosan popular in food industry, textile industry, environmental protection, medicine and health care and other fields. And its source and abundant reserves make the development and application of chitosan materials have dual meanings of improving the quality of human life and making full use of natural resources. [0003] The polysaccharide unit structure of chitosan determines that there are a large number of hydrogen bonds in and be...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): A61L15/28A61L15/42A61K47/36A61K9/06
Inventor 胡巧玲聂景怡王征科
Owner ZHEJIANG UNIV
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