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Semi-dry microwave synthesis of carboxymethyl chitosan

A technology for carboxymethyl chitosan and microwave synthesis, applied in microwave heating and other directions, can solve the problems of large consumption of organic solvents, unsafe workshops, large energy consumption, etc., and achieve the effects of reducing reagent dosage, production safety, and cost reduction.

Inactive Publication Date: 2002-01-02
唐梓进 +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0002] At present, carboxymethyl chitosan is synthesized in a liquid organic solvent, and reflux condensation is required. The synthesis time generally takes 5 and a half hours, consumes a large amount of organic solvent, and the workshop is not safe, and the treatment and recovery of the organic solvent takes a year. Equipment and manpower, consume a lot of energy

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  • Semi-dry microwave synthesis of carboxymethyl chitosan
  • Semi-dry microwave synthesis of carboxymethyl chitosan

Examples

Experimental program
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Effect test

Embodiment 1

[0021] Embodiment 1: 20 kilograms of chitosan of purification is ultrafinely pulverized, add 50 kilograms of 35% sodium hydroxide NaOH, 0.1 kilogram of 30% hydrogen peroxide, 100W microwave 5 minutes, put about-20 ℃ of freezing, add 20 after thawing After stirring evenly with 35% sodium hydroxide NaOH in kilograms, microwave at 300W three times, 5 minutes each time, and cool with 4°C cold wind after each microwave. Then add 5 kg of catalyst polyethylene glycol and 5 kg of dimethyl sulfoxide, stir, and microwave at 300W for 5 minutes. After cooling, add 50 kg of chloroacetic acid, add in five equal parts five times, microwave at 300W for 5 minutes after each addition. After each microwave, it must be cooled by cold air at 4°C. Add chloroacetic acid for the last time and finish the reaction. After cooling, microwave at 300W twice for 5 minutes each time. Cool with cold air at 4°C after each microwave. Then add 20 kilograms of 35% sodium hydroxide NaOH, stir evenly, 200W micro...

Embodiment 2

[0022] Embodiment 2: 50 kilograms of chitosan fine powder through superfine pulverization after purification, add 500 kilograms of 35% sodium hydroxide NaOH, 0.8 kilogram of hydrogen peroxide, 200W microwave 5 minutes, put-18 ℃ of freezing, add 100 kilograms after thawing Kilograms of 35% sodium hydroxide NaOH were stirred evenly, then microwaved at 500W three times for 5 minutes each time, and cooled with cold air at 4°C after each microwave. Then add 5 kg of catalyst p-toluenesulfonic acid and 35 kg of dimethyl sulfoxide, stir evenly and microwave at 500W for 5 minutes, and cool with cold air. Then add 150 kg of chloroacetic acid, add in five equal parts five times, microwave at 200W for 5 minutes after each addition, and cool with cold wind after each microwave. After all is finished, add 100 kg of sodium hydroxide NaOH and stir evenly. Microwave at 200W five times for 6 minutes each time. After each microwave, it must be cooled with 4°C cold air to make carboxymethyl chito...

Embodiment 3

[0023] Embodiment 3: 35 kilograms of chitosan of purification is ultrafinely pulverized, add 350 kilograms of 35% sodium hydroxide NaOH, 0.4 kilogram of 30% hydrogen peroxide, 100W microwave 5 minutes, put about-19 ℃ of freezing, add 60 after thawing After stirring evenly with 35% sodium hydroxide NaOH in kilograms, microwave at 300W three times, 5 minutes each time, and cool with 10°C cold wind after each microwave. Next, 25 kg of catalyst polyethylene glycol and 25 kg of dimethyl sulfoxide were added, and after stirring, microwave at 300W for 5 minutes. After cooling, add 100 kg of chloroacetic acid in five equal portions, and microwave at 300W for 6 minutes after each addition. After each microwave, it must be cooled with cold air at 10°C. Add chloroacetic acid for the last time and finish the reaction. After cooling, microwave at 500W twice for 5 minutes each time. Cool with 10°C cold air after each microwave. Then add 60 kilograms of 35% sodium hydroxide NaOH, stir eve...

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Abstract

The present invention relates to a new process for synthesizing carboxymethyl chitosan by using semi-dry microwave method under the condition of having no organic solvent, and the said process includes the following steps: using purified ultramicro-pulverized chitosan 20-50 weight portions, adding 35% sodium hydroxide solution 50-500 weight portions, adding activating agent 30% hydrogen peroxide 0.1-0.8 weight portion, uniformly mixing them and placing them into a reactor, adopting 100-300 W microwave for 5-10 min., cooling below 10 deg.C, defreezing and then adding 30% sodium hydroxide and microwave treatment for three times, cooling, further adding sodium hydroxide, microwave treatment, cooling so as to obtain the finished product, then using methyl alcohol and ethyl alcohol to remove excess chloroacetic acid and sodium hydroxide so as to obtain pure product.

Description

technical field [0001] The invention relates to a novel process for synthesizing carboxymethyl chitosan from chitosan by semi-dry microwave under the condition of no organic solvent. Background technique [0002] At present, carboxymethyl chitosan is synthesized in a liquid organic solvent, and reflux condensation is required. The synthesis time generally takes 5 and a half hours, consumes a large amount of organic solvent, and the workshop is not safe, and the treatment and recovery of the organic solvent takes a year. Equipment and manpower consume a lot of energy. Contents of the invention [0003] The present invention provides a semi-dry method microwave synthesis of carboxymethyl chitosan in view of the above-mentioned deficiencies. In the synthesis process, activators and catalysts are used to completely eliminate organic solvents, and microwave catalysis is used to realize the semi-dry microwave synthesis of carboxymethyl chitosan. The purpose of the base chitosan...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08B37/08H05B6/64
Inventor 唐梓进
Owner 唐梓进
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