Novel preparation method for oxidized cellulose

A technology for oxidizing cellulose and cellulose, applied in the field of preparing oxidized cellulose, can solve the problems of poor thermal conductivity of regenerated cellulose, low energy consumption and efficiency, high degradation of products, etc. The effect of increasing the coefficient and reducing side reactions

Active Publication Date: 2017-04-26
HANGZHOU SINGCLEAN MEDICAL PROD +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The selective oxidation degree of the primary hydroxyl group in this system is relatively good, but there are also many disadvantages: ①The oxidized product is yellow to brown due to the nitrogen content; ②Because the system is a gaseous heterogeneous reaction, the product is highly degraded; ③The oxidation reaction Too slow, generally takes 60 ~ 70h
Impurities such as alcohol, isopropanol, and water exist in the regenerated cellulose fiber. Because the thermal conductivity of regenerated cellulose is not good, it is difficult to remove water, alcohol, etc. by general vacuum drying. Freeze drying is usually used, and the energy consumption and efficiency are low.

Method used

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  • Novel preparation method for oxidized cellulose

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Experimental program
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Effect test

Embodiment 1

[0035] 1) In the external circulation pulsating reactor, add cellulose fiber fabric (denier 150 denier) raw materials, open the external circulation pump for oxygen removal and nitrogen replacement protection; open the heat exchanger;

[0036] 2) After the replacement of deoxygenation and nitrogen filling is complete, the system is evacuated;

[0037] 3) Slowly open the nitrogen dioxide pipeline, open the nitrogen pipeline, the mixed gas is pumped in, the nitrogen dioxide volume concentration is 55%, and passes through the heat exchanger to control the air flow temperature at 0 ° C in the reactor and the cellulose The raw materials are contacted, a selective oxidation reaction occurs, and the cycle reaction is continuously carried out to promote the completion of the reaction. The pressure in the reactor is -0.090MPa. Wherein, the gas circulation switch in the external circulation oxidation reactor is closed and opened to perform gas flow pulsation at a pulsation ratio of 20s...

Embodiment 2

[0041] 1) In the external circulation pulsating reactor, add regenerated cellulose fiber fabric (denier 0.5 denier) raw materials, open the external circulation pump for oxygen removal and nitrogen replacement protection; open the heat exchanger;

[0042] 2) After the replacement of deoxygenation and nitrogen filling is complete, the system is evacuated;

[0043] 3) Slowly open the nitrogen dioxide pipeline, open the nitrogen pipeline, the mixed gas is pumped in, the nitrogen dioxide volume concentration is 1%, and passes through the heat exchanger to control the air flow temperature at 160 ° C in the reactor and the cellulose The raw materials are contacted, a selective oxidation reaction occurs, and the cycle reaction is continuously carried out to promote the completion of the reaction. The pressure in the reactor was 1.0 MPa. Wherein, the air flow circulation switch in the external circulation oxidation reactor is closed and opened to perform air flow pulsation at a pulsa...

Embodiment 3

[0047] 1) Add regenerated cellulose non-woven fabric (denier 3.0 denier) raw materials into the external circulation pulsating reactor, turn on the external circulation pump for oxygen removal and nitrogen replacement protection; turn on the heat exchanger;

[0048] 2) After the replacement of deoxygenation and nitrogen filling is complete, the system is evacuated;

[0049] 3) Slowly open the nitrogen dioxide pipeline, open the nitrogen pipeline, the mixed gas is pumped in, the nitrogen dioxide volume concentration is 2%, and passes through the heat exchanger to control the air flow temperature at 80 ° C in the reactor and the cellulose The raw materials are contacted, a selective oxidation reaction occurs, and the cycle reaction is continuously carried out to promote the completion of the reaction. The pressure in the reactor was 0.0 MPa (gauge pressure). Wherein, the gas circulation switch in the external circulation oxidation reactor is closed and opened to perform gas flo...

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Abstract

The invention discloses a novel preparation method for oxidized cellulose. The preparation method comprises the following steps that cellulose raw materials are added into an external circulation pulsatile-typed reactor; an external circulation pump is started to conduct deoxidizing and nitrogen filling replacement protection; a heat exchanger is started; and after the deoxidizing and nitrogen filling replacement is finished, a system is vacuumized. Through dilution of nitrogen, the concentration of hyper-responsiveness nitrogen dioxide is adjustable, and therefore an oxidation reaction can be controlled more moderately, the side reactions such as degradation of a product occur less, and selectivity and the yield of the reaction are improved. According to the novel preparation method for the oxidized cellulose, the reaction can be conducted under negative pressure and a low temperature, so that not only is the occurrence of various side reactions further reduced, but also the security coefficient of the reaction system is greatly improved. The novel preparation method for the oxidized cellulose is strong in adaptability, the applicable cellulose raw materials are cellulose or regenerated cellulose, and the raw material form can be textile fabrics, non-woven fabrics or cellulose membranes.

Description

technical field [0001] The present invention relates to a new preparation method of oxidized cellulose. Background technique [0002] Cellulose is a macromolecular polysaccharide composed of glucose. Insoluble in water and general organic solvents. It is the main component of plant cell wall. 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. At room temperature, cellulose is neither soluble in water nor in general organic solvents, such as alcohol, ether, acetone, benzene, etc. It is also insoluble in dilute alkaline solutions. Therefore, at normal temperature, it is relatively stable because of the presence of hydrogen bonds between cellulose molecules. Cellulose is insoluble in water and organic solvents such as ethanol and ether, but soluble in cuproammonia Cu(NH 3 ) 4 (OH) 2 solution and copper ethylenediamine [NH 2 CH 2 CH 2 NH 2 ]Cu(OH) 2 solution et...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08B15/02
CPCC08B15/02
Inventor 张治国黄伟索艳格
Owner HANGZHOU SINGCLEAN MEDICAL PROD
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