| 摘要 |
An aqueous LiOH solution containing 2.0-3.5 mol/kg LiOH is proposed for dissolving cellulose. An even better effect is displayed by an LiOH/NaOH solution containing 2.0-4.5 mol/kg total alkali metal, with the Na/Li molar ratio expediently being 0.3-1.5, preferably about 1.0. Addition of an N-containing carbonic acid derivative, in particular 0.5-2.0 mol/kg urea, further increases the solubility of cellulose. To dissolve cellulose, the latter is expediently dispersed at ambient temperature in the solvent, the dispersion is cooled to a temperature between -5 DEG and -20 DEG C, whereupon solution occurs, and subsequently the solution is allowed to warm to room temperature again. Regenerated cellulose can be precipitated by conventional methods from the solutions according to the invention.
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