A green, fast and efficient methylation method for cellulose

A cellulose and methylation technology, applied in the field of green, fast and efficient chemical modification, can solve the problems of harsh reaction conditions, low efficiency of primary methylation, expensive and highly toxic, and achieve low cost, thickening and emulsifying effects. Significant, shortened response time effect

Inactive Publication Date: 2017-02-01
XIAN UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a green, fast and efficient methylation method for cellulose, which solves the problems of expensive and highly toxic methylation reagents, harsh reaction conditions, and low efficiency of the primary methylation reaction in the prior art

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0032] (1) Soak 8 parts (parts by mass) of absorbent cotton in 3% sodium hydroxide-dimethyl sulfoxide activator solution, activate it under ultrasonic conditions for 0.5 hours, activate ultrasonically for 10 minutes each time, and then stop for 10 minutes , and then ultrasonically activated for 10 minutes, and so on, and filtered to remove excess activator solution, and washed with water until the pH value of the aqueous phase was 7;

[0033] (2) Add 0.25 gram of urea, 40 parts (parts by mass) of dimethyl carbonate add in four times, add dimethyl carbonate each time and react under 100% microwave conditions for 20 seconds, then continue to stir but stop the microwave effect 20 seconds, and then 20 seconds of microwave action, and so on, 1 minute of microwave action, a total of 4 minutes of microwave action, the obtained product is cooled, filtered, washed, dried, and pulverized to obtain methyl cellulose.

[0034] cellulosic 1 H NMR spectra at δ4.41, δ3.55, δ3.58, δ3.72, δ3.3...

Embodiment 2

[0037] (1) Soak 10 parts (mass parts) of cotton linters in 5% sodium hydroxide-dimethyl sulfoxide activator solution, and activate them under ultrasonic conditions for 1.0 hour, each ultrasonic activation for 10 minutes, and then stop 10 minutes, and then ultrasonically activated for 10 minutes, and so on, and filtered to remove excess activator solution, washed with water until the pH of the aqueous phase was 8;

[0038] (2) Add 0.25 gram urea and 0.25 gram disodium hydrogen phosphate, 50 parts (mass parts) dimethyl carbonate adds in five times, add dimethyl carbonate at every turn and react under 100% microwave condition for 20 seconds, then Continue to stir but stop the microwave action for 20 seconds, and then microwave for 20 seconds, and so on. The microwave action is 1 minute, and the microwave action is 5 minutes in total. After cooling, the obtained product is filtered, washed, dried, and pulverized to obtain methyl cellulose.

[0039] The methyl cellulose that embodi...

Embodiment 3

[0042] (1) 12 parts (parts by mass) of wheat straw were soaked in 10% sodium hydroxide-dimethyl sulfoxide activator solution, activated under ultrasonic conditions for 2.0 hours, each time ultrasonically activated for 10 minutes, and then stopped for 10 minutes , and then ultrasonically activated for 10 minutes, and so on, and filtered to remove excess activator solution, washed with water until the pH value of the aqueous phase was 8.5;

[0043] (2) Add 0.50 gram of urea and 0.50 gram of disodium hydrogen phosphate, 60 parts (parts by mass) of dimethyl carbonate add in six times, react under 100% microwave conditions for 20 seconds after each addition of dimethyl carbonate, and then Continue to stir but stop the microwave action for 20 seconds, and then microwave for 20 seconds, and so on. The microwave action is 1 minute, and the microwave action is 6 minutes in total. After cooling, the obtained product is filtered, washed, dried, and pulverized to obtain methyl cellulose. ...

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Abstract

The invention discloses a green quick high-efficiency methylation method of cellulose, which comprises the following steps: immersing 8-12 parts of cellulose in 18-22 parts of activator solution, carrying out activating treatment under ultrasonic conditions, carrying vacuum filtration to remove the excess activator solution, washing with water until the pH value of the water phase is 7-9, adding 4-6 parts of catalyst and 40-60 parts of dimethyl carbonate, reacting under 100% microwave conditions for 4-12 minutes, cooling the obtained product, carrying out vacuum filtration, washing, drying and pulverizing. The green quick high-efficiency methylation method of cellulose adopts the green environment-friendly dimethyl carbonate as a methylation reagent, and the methylation process can be implemented under the conditions of normal temperature and pressure. The method has the advantages of low cost, simple technique, environment friendliness and no discharge of toxic and harmful gas or waste.

Description

technical field [0001] The invention belongs to a green, fast and efficient chemical modification method of natural polysaccharide polymers, in particular to a green, fast and efficient methylation method of cellulose. Background technique [0002] Cellulose is the most widely distributed and most abundant polysaccharide in nature, accounting for more than 50% of the carbon content in the plant kingdom. Among them, the cellulose content of cotton is close to 100%, which is the purest natural cellulose source. Cellulose is a macromolecular polysaccharide composed of glucose. Methylcellulose is a cellulose derivative obtained by replacing the hydrogen atom on the hydroxyl group of cellulose with a methyl group. It has excellent wettability, dispersibility, adhesiveness, thickening, emulsification, water retention and film-forming properties. , can be widely used in food, medicine, textile, building materials, metallurgy and many other industrial fields. [0003] Traditionall...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C08B11/10C08B1/06
Inventor 侯成敏
Owner XIAN UNIV OF TECH
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