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

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...