Protic ionic liquid, preparation method and application of protic ionic liquid in cellulose dissolution and regeneration

Abstract

The invention discloses protic ionic liquid used for dissolving cellulose. The components of the protic ionic liquid are shown in a formula of HB+A-, wherein B is sulfur-containing organic or inorganic compound, and A is 98 mass percent concentrated sulfuric acid. The preparation method comprises the following steps of: slowly dripping sulfuric acid into a sulfur-containing compound, and stirring to obtain the protic ionic liquid. The system is used for cellulose dissolution and regeneration and has high capacity of dissolving the cellulose, and after the system is fully stirred at room temperature, the cellulose dissolubility is 10 to 30 percent. The dissolved cellulose is subjected to a wet spinning technology, ethanol is used as setting liquid, drawing molding is carried out, and a solvent is recovered. The cellulose is directly dissolved in the prepared protic ionic liquid, and the cellulose dissolubility is obviously improved. Flows such as alkalization and sulfonation in the production process are simplified, and the problem of environmental pollution due to fiber processing is solved; moreover, the fiber production cost can be reduced and the quality stability of the fiber is improved.

Description

technical field [0001] The invention relates to a proton-type ionic liquid and its application in cellulose dissolution, belonging to the technical field of cellulose regeneration. Background technique [0002] Cellulose fiber is the first regenerated fiber to become a textile fiber. It has the advantages of comfortable wearing and good air permeability, so it has a wide range of uses in the fields of textiles and clothing. Cellulose (C 6 h 10 o 5 )n is a linear macromolecule formed by connecting D2 glucopyranose anhydroglucopyranose with β-1,4 glycosidic bonds. , The 4-carbon position is firmly connected. This structure makes the cellulose macromolecules form a complex structure of strong hydrogen bonds and the coexistence of crystalline and amorphous regions within and between molecules, making it difficult for cellulose to dissolve in common solvents to form a true solution. Therefore, seeking a new cellulose solvent with simple process, safe and effective has always...

AI Technical Summary

Problems solved by technology

In the past 30 years, scientists from various countries have devoted themselves to the research of cellulose solvent systems with little environmental pollution, such as: paraformaldehyde / dimethylsulfoxide (PF / DMSO) system, dinitrogen tetroxide / dimethylformamide (N2O4 / DMF) system, lithium chloride / dimethylacetamide (LiCl / DMAc) system, dimethyl sulfoxide / tetraethylammonium chloride (DMSO / TEAC) system, ammonia / ammonium thiocyanate (NH3 / NH4SCN) Both solvent systems such as amine oxide system and amine oxide have certain solubility to cellulose, but there are disadvantages such as difficulty in solvent recovery, defective fiber structure and uneven quality.

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