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Method for preparing chitosan derivative by ultrasonic field strengthening location

A technology of chitosan derivatives and ultrasonic field, which is applied in the field of preparation of chitosan derivatives, can solve the problems of large amount of reactants, long reaction time, and low derivation efficiency, and achieve the goal of improving reaction efficiency and good adsorption Effect

Inactive Publication Date: 2011-04-27
SOUTH CHINA UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The traditional derivatization method is to carry out the derivatization reaction without the action of an external physical field, the reaction time is long, the amount of reactants is large, and the derivation efficiency is low

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0019] Step 1: Preparation of chitosan derivatives under weakly acidic conditions strengthened by ultrasonic field.

[0020] 1. Dissolve chitosan in 3% acetic acid solution (pH 1.0), swell for 2.5 hours, add absolute ethanol to dilute, and prepare a 5 mg / ml chitosan solution.

[0021] 2. Slowly add formaldehyde dropwise so that the molar ratio of chitosan: formaldehyde is 1:4.

[0022] 3. Put the above reaction system at 150W / cm 2 Under an ultrasonic field, at 80° C., the reaction was stirred and refluxed for 2 h, and the pH value of the solution was finally adjusted to 2.0.

[0023] 4. Filtrate, wash with absolute ethanol and ether, and then vacuum-dry at a constant temperature to obtain the crude product of chitosan formaldehyde Schiff base.

[0024] Step 2: Purification of crude chitosan derivative products.

[0025] The obtained crude product was repeatedly refluxed and extracted with 95% ethanol in a Soxhlet extractor for 8 hours to obtain a pure chitosan formaldehyde ...

Embodiment 2

[0028] Step 1: Preparation of chitosan derivatives under weakly acidic conditions strengthened by ultrasonic field.

[0029] 1. Dissolve chitosan in 4% acetic acid solution (pH 3.5), swell for 3.5 hours, add absolute ethanol to dilute, and configure 4 mg / ml chitosan solution.

[0030] 2. Slowly add a certain amount of formaldehyde dropwise, so that the molar ratio of chitosan: formaldehyde is 1:6.

[0031] 3. Put the above reaction system at 120W / cm 2 Under the ultrasonic field, at 70°C, stir and reflux for 4 hours, and finally adjust the pH value of the solution to 3.0.

[0032] 4. Filtrate, wash with absolute ethanol and ether, and then vacuum-dry at a constant temperature to obtain the crude product of chitosan formaldehyde Schiff base.

[0033] Step 2: Purification of crude chitosan derivative products.

[0034] The obtained crude product was repeatedly refluxed and extracted for 12 hours in a Soxhlet extractor with 95% ethanol to obtain a pure chitosan formaldehyde Sch...

Embodiment 3

[0037] Step 1: Preparation of chitosan derivatives under weakly acidic conditions strengthened by ultrasonic field.

[0038] 1. Dissolve chitosan in 5% acetic acid solution (pH 2.5), swell for 4.5 hours, add absolute ethanol to dilute, and configure a 2 mg / ml chitosan solution.

[0039] 2. Slowly add a certain amount of formaldehyde dropwise, so that the molar ratio of chitosan: formaldehyde is 1:8.

[0040] 3. Put the above reaction system at 90W / cm 2 Under an ultrasonic field, at 60° C., stirring and refluxing for 6 hours, the final pH value of the solution was adjusted to 4.0.

[0041] 4. Filtrate, wash with absolute ethanol and ether, and then vacuum-dry at a constant temperature to obtain the crude product of chitosan formaldehyde Schiff base.

[0042] Step 2: Purification of crude chitosan derivative products.

[0043] The obtained crude product was repeatedly refluxed and extracted with 95% ethanol in a Soxhlet extractor for 16 hours to obtain a pure chitosan formald...

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Abstract

The invention discloses a site-specific preparation method of ultrasonic field reinforced chitosan derivatives. The method comprises the following steps: dissolving chitosan in acetic acid solution, swelling for 2-5h, adding anhydrous alcohol for dilution to realizes that final concentration of the chitosan is 2-5mg / ml; then adding aldehydes with the mol ratio of the chitosan and the aldehyde being 1:3-7; placing the obtained mixture in an ultrasonic field with 90-150W / cm<2> ultrasonic power intensity, and allowing reflux reaction at constant temperature of 60-80 DEG C for 1-6h to obtain a crude product of the chitosan derivatives. The crude product is filtered, washed with anhydrous alcohol and ether, dried in vacuum at a constant temperature, and subject to repeated reflux extraction with 95% alcohol to obtain a biological pure product of the chitosan derivatives. A site-spefific preparation process of the ultrasonic field reinforced chitosan derivatives is introduced in the method to improve efficiency of a condensation reaction and prepare a series of chitosan derivatives with excellent adsorptivity and flocculability. The derivatives have extensive application prospect in a plurality of fields, such as medicine, environmental protection, food fields and the like.

Description

technical field [0001] The invention relates to the preparation of chitosan derivatives, in particular to a method for preparing chitosan derivatives by introducing an external ultrasonic field to enhance positioning. Background technique [0002] Chitosan (Chitosan, CS) is the product of deacetylation of natural polymer chitin, which is composed of β-(1,4)-2-amino-2-deoxy-D-glucose units and β-(1,4) - A copolymer of 2-acetylamino-2-deoxy-D-glucose units. Compared with other polymer materials, chitosan has the characteristics of biodegradability, non-toxicity, and good biocompatibility. In recent years, it has been more and more widely used in food, medicine, cosmetics, chemical industry, and environmental protection. Chitosan has good adsorption properties, especially for transition metal ions. But because it is an alkaline polysaccharide, it will be affected by the -NH in the molecule in an acidic environment 2 is protonated to form -NH 3 + And soluble in water to cau...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C08B37/08
Inventor 郭祀远段丽红王兆梅郑必胜肖凯军叶盛权杨晋青
Owner SOUTH CHINA UNIV OF TECH
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