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Method for preparing nanometer nitro celluloses

A technology of nitrocellulose and nanocellulose, which is applied in the field of preparation of nanometer nitrocellulose, can solve the problems of poor stability of nitrocellulose, pollution in nitrocellulose production, complicated post-treatment and reuse of waste acid, etc., and achieves shortened nitration time, The effect of improving stability

Active Publication Date: 2010-09-22
BEIJING INSTITUTE OF TECHNOLOGYGY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Since the nitrification liquid contains sulfuric acid and nitric acid, the post-treatment and reuse of waste acid is very complicated.
This has also become the root cause of serious pollution in the production of nitrocellulose
In addition, the cellulose sulfate formed by the reaction of sulfuric acid in the nitrating liquid and cellulose is one of the main factors causing the poor stability of nitrocellulose

Method used

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  • Method for preparing nanometer nitro celluloses
  • Method for preparing nanometer nitro celluloses
  • Method for preparing nanometer nitro celluloses

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0023] (1) Preparation of nanocellulose suspension

[0024] Cotton cellulose powder was ultrasonically pretreated in an ice bath for 15 minutes, filtered and dried for later use.

[0025] Immerse 0.5g of the above-mentioned cellulose powder accurately weighed in 8.75ml of sulfuric acid solution with a concentration of 64wt%, stir and react in a water bath at 45°C for 1h, then add 10 times the volume of deionized water to dilute the reaction solution; the diluted reaction The solution was centrifuged at 8000 rpm; the suspension was dialyzed in deionized water for 24 hours until the pH value was the same as that of the deionized water used. The molecular weight cut-off of the dialysis bag used is 8000-14000; finally, after ultrasonic dispersion with a power of 150w for 15 minutes, a stable suspension of nanocellulose whiskers is obtained, wherein the nanocellulose whiskers have a diameter of 20-30nm and a length of 150- 250nm. The morphology of the prepared nanocellulose whisk...

Embodiment 2

[0029] (1) Preparation of nanocellulose suspension

[0030] Cotton cellulose powder was ultrasonically pretreated in an ice bath for 15 minutes, filtered and dried for later use.

[0031] Immerse 0.5g of the above-mentioned cellulose powder accurately weighed in 25ml of sulfuric acid solution with a concentration of 64wt%, stir and react in a water bath at 60°C for 4h, then add 10 times the volume of deionized water to dilute the reaction solution; the diluted reaction solution Centrifuge at 8000 rpm; dialyze the suspension in deionized water for 24 hours until the pH is the same as that of the deionized water used. The molecular weight cut-off of the dialysis bag used is 8000-14000; finally, after ultrasonic dispersion with a power of 150w for 15 minutes, a stable nanocellulose whisker suspension is obtained, wherein the nanocellulose whiskers have a diameter of 20-30nm and a length of 100- 150nm. The morphology of the prepared nanocellulose whiskers is shown in the transmi...

Embodiment 3

[0035] (1) Preparation of nanocellulose suspension

[0036] Cotton cellulose powder was ultrasonically pretreated in an ice bath for 15 minutes, filtered and dried for later use.

[0037] Immerse 0.5g of the above-mentioned cellulose powder accurately weighed in 16ml of sulfuric acid solution with a concentration of 64wt%, stir and react in a water bath at 75°C for 8h, then add 10 times the volume of deionized water to dilute the reaction solution; the diluted reaction solution Centrifuge at 8000 rpm; dialyze the suspension in deionized water for 24 hours until the pH is the same as that of the deionized water used. The molecular weight cut-off of the dialysis bag used is 8000-14000; finally, after 150w ultrasonic dispersion for 15min, a stable nanocellulose whisker suspension is obtained. Wherein, the nanocellulose whiskers have a diameter of 15-20nm and a length of 100-200nm. The morphology of the prepared nanocellulose whiskers is shown in the transmission electron micros...

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Abstract

The invention relates to a method for preparing nanometer nitro celluloses, and belongs to the technical field of special chemical engineering. The preparation method comprises the following steps of: 1, performing ultrasonic pre-treatment on cotton cellulose powder in ice bath, and performing pumping filtration and drying on the cotton cellulose powder for later use; and soaking the cellulose powder in sulfuric acid solution at a certain concentration, controlling a solid-liquid ratio within 17.5 to 50g / mL, stirring the mixed solution to perform reaction in water bath at the temperature of between 45 and 75 DEG C for certain time, adding water to dilute the mixed solution, performing the centrifugal separation on the reaction solution until a pH value of the mixed solution is 6 to 7, and ultrasonically dispersing the mixed solution to obtain the stable nanometer cellulose crystal whisker suspension; 2, adding a proper amount of nitric acid into the nanometer cellulose crystal whisker suspension so as to make the nanometer cellulose crystal whisker suspension reach the needed concentration, adding water to dilute the mixed solution, and performing centrifugation and washing until the pH value of the mixed solution is 6 to 7; and 3, moving precipitates to an evaporating dish, and performing vacuum drying on the precipitates at the temperature of 50 DEG C to obtain the nanometer nitro cellulose powder. In the method, because the composition of the acid is single, the post-treatment and the reutilization of the acid are convenient; and the nitrifying time is shortened, and the stability is improved; and the nanometer nitro celluloses can be used as the energetic reinforcing materials.

Description

technical field [0001] The invention relates to a preparation method of nanometer nitrocellulose, which belongs to the technical field of special chemical industry. Background technique [0002] Nitrocellulose is an energetic chemical material widely used in gunpowder, explosives and propellants. Since most of the raw materials used in the preparation of nitrocellulose in my country are cotton cellulose, nitrocellulose is also commonly called nitrocellulose. At present, the traditional process of preparing nitrocellulose with refined cotton as raw material is: use nitric acid / sulfuric acid / water as the nitration liquid, and the nitration time is 30 minutes. By adjusting the ratio of nitric acid / sulfuric acid / water in the nitrating liquid, the nitrocellulose with the highest nitrogen content of about 13.5% can be obtained. Since the nitrification liquid contains sulfuric acid and nitric acid, the post-treatment and reuse of waste acid is very complicated. This has also bec...

Claims

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Application Information

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IPC IPC(8): C08B15/06C08J3/12C08J3/05C06B25/18C06B25/28C06D5/00
Inventor 王文俊邵自强张凤侠王飞俊李永红
Owner BEIJING INSTITUTE OF TECHNOLOGYGY
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