A kind of method for improving 1-allyl-3-methylimidazolium chloride dissolving cellulose performance

Abstract

The invention discloses a method for improving the capability of 1-allyl-3-methylimidazole chloride to dissolve cellulose and belongs to the field of cellulose dissolution methods. The method includes: drying cellulose to less than 1% in water content, adding 1-allyl-3-methylimidazole chloride, adding a solid acid, and stirring and dissolving at 60-120 DEG C. Anions in the solid acid and cations of the 1-allyl-3-methylimidazole chloride act on hydroxyls of cellulose molecules, hydrogen bonds in and between the cellulose molecules are destroyed to great extent, and the capability of an ionic liquid to dissolve the cellulose is improved. Ineffective degradation of the ionic liquid of the 1-allyl-3-methylimidazole chloride during cellulose dissolution is effectively restrained, the structure of the ionic liquid is stabilized, steam pressure is zero, repeatability is available, and greenness is achieved; the solid acid is free of pollution, easy to recycle and reusable, reducing cost.

Description

technical field [0001] The invention relates to the field of cellulose dissolving methods, in particular to a method for improving the performance of 1-allyl-3-methylimidazolium chloride salt in dissolving cellulose. Background technique [0002] Cellulose is the most abundant natural polymer resource on the earth. It has the advantages of renewability, biodegradability and homogeneity. It has become an important raw material for traditional industries such as pulp and paper, textile, polymer materials and medicine. With the depletion of traditional non-renewable resources such as oil and coal on the earth, the sustainable development of energy and materials is imminent. Therefore, how to efficiently develop and utilize renewable resources such as cellulose has become an important problem in the sustainable development strategy of the world today. [0003] The conversion of fiber resources into chemicals, materials and biofuels has received extensive attention, but plant fi...

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Problems solved by technology

[0003] The conversion of fiber resources into chemicals, materials and biofuels has received extensive attention, but plant fibers are difficult to dissolve in most solvents due to the high degree of polymerization, high hydrophobicity, highly ordered structure and extensive hydrogen bond network structure , which seriously hinders its efficient transformation and deep processing

To improve cellulose conversion efficiency, some cellulose solvent systems have been developed, including N,N-dimethylacetamide / lithium chloride (DMAc / LiCl), N,N-dimethylformamide / nitrogen tetroxide ( DMF / N2O4), N-methyl-N-oxymorpholine (NMMO), dimethylsulfoxide / tetrabutylammonium fluoride (DMSO / TBAF) and molten salt hydrates (such as LiClO4·3H2O, LiSCN· 2H2O), but these solvent systems more or less have the following disadvantages: strong toxicity, high cost, difficult solvent recycling and instability during use, etc.

At present, the research on 1-allyl-3-methylimidazolium chloride salt focuses on the dissolution and modification of cellulose, but the solubility of 1-allyl-3-methylimidazolium chloride salt to cellulose is not very good. Well, the dissolution temperature is high, the solubility is low, and the dissolution time is long; in addition, during the dissolution process, the thermal degradation of 1-allyl-3-methylimidazolium chloride salt is serious

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