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Lithium hydrate and carbamide composition solvent for dissolving cellulous fiber and its use

A technology for dissolving cellulose and lithium hydroxide, which is applied to the chemical characteristics of fibers, single-component cellulose rayon, textiles and papermaking, etc. It can solve the problems of incomplete dissolution of cellulose and inability to obtain concentrated cellulose solutions. Achieve the effects of wide application, simple process and high molecular weight

Inactive Publication Date: 2004-11-17
WUHAN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the disadvantage of this system is that higher molecular weight cellulose cannot be completely dissolved, and a high molecular weight cellulose concentrated solution cannot be obtained

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0015] 200 g of 3.0 wt% LiOH / 30.0 wt% urea mixed aqueous solution was added with 20.0 g of regenerated cellulose (viscose staple fiber, polymerization degree 300) and stirred, then placed in a refrigerator to freeze for 3-5 hours. After being completely frozen into a solid, thaw at room temperature and stir to obtain a transparent cellulose solution. Use an ultracentrifuge at 10,000 rpm at 15°C for 30 minutes to degas it to obtain a transparent cellulose solution (code SI-C3), and there is no micelle precipitate at the bottom of the centrifuge cylinder.

Embodiment 2

[0017] 200 grams of 7.0wt% LiOH / 4.0wt% urea mixed aqueous solution was added to 8.4 grams of wood pulp cellulose (polymerization degree 460) and stirred, then placed in a refrigerator to freeze for 3 to 5 hours. After being completely frozen into a solid, thaw at room temperature and stir to obtain a transparent cellulose solution. Use an ultracentrifuge at 10,000 rpm at 15°C for 30 minutes to degas it to obtain a transparent cellulose solution (code SI-C4), with no micelle precipitate at the bottom of the centrifuge cylinder.

Embodiment 3

[0019] 200 grams of 5.0wt% LiOH / 10.0wt% urea mixed aqueous solution was added to 12.8 grams of cotton linter pulp (polymerization degree 500) and stirred, then placed in a refrigerator to freeze for 3 to 5 hours. After being completely frozen into a solid, thaw at room temperature and stir to obtain a transparent cellulose solution. Use an ultracentrifuge at 10,000 rpm at 15°C for 30 minutes to degas it to obtain a transparent cellulose solution (code SI-C5), with no micelle precipitate at the bottom of the centrifuge cylinder.

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PUM

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Abstract

The invention relates to a dissolvent for cellulose dissolution through freezing-unfreezing method or direct dissolution method, and process for preparing the regenerated cellulose fibers and films by utilizing the dissolvent, wherein the dissolvent is the water solution of lithium hydroxide and urea whose compositions are 3.0-7.0wt% of lithium hydroxide, 4.0-30.0.0wt% of urea, the rest is water. The water solution of lithium hydroxide and urea can directly dissolve cellulose through freezing-unfreezing method or by pre-cooling the dissolvent in advance to -10 deg. C - -4 deg. C. It can be used to obtain high dissolvability transparent concentrated cellulose solution. By using the concentrated cellulose solution and through 3-5wt% diluted acid water solution coagulation, regeneration, regenerated cellulose films and fibers can be prepared.

Description

technical field [0001] The present invention relates to a new solvent for cellulose using a mixed aqueous solution of lithium hydroxide and urea, and a new method for dissolving cellulose and preparing regenerated cellulose filaments and membranes, belonging to the field of natural macromolecules, and also belonging to chemistry, agriculture, field of environmental engineering. Background technique [0002] Plant cellulose is the most abundant renewable resource on the earth. It is an environmentally friendly polymer material and is expected to become one of the main chemical raw materials in the 21st century. However, cellulose is far from being fully utilized in the chemical industry at present, mainly because the cellulose dissolution process in the existing process is complicated, costly and polluting. At present, more than 90% of regenerated cellulose products are still produced by the traditional viscose method, and the cellulose is mixed with CS under the action of s...

Claims

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Application Information

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IPC IPC(8): C08J3/02C08K5/21C08L1/02
CPCD01D1/02D01F2/00
Inventor 张俐娜蔡杰
Owner WUHAN UNIV
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