METHOD OF PRODUCING MICROCRYSTALLINE OR NANOCRYSTALLINE CELLULOSE Russian patent published in 2024 - IPC C08L1/00 C08B15/02 C08B15/08 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing micro- or nanocrystalline cellulose compositions from cellulose. Disclosed is a method of producing microcrystalline or nanocrystalline cellulose from primary cellulose containing amorphous and crystalline phases of cellulose, involving the following steps: (A) bringing primary cellulose into contact with a first solvent, characterized by that the first solvent is an aqueous solution containing 40–65 wt.% of ZnCl₂ in water relative to the total weight of ZnCl₂ and water, wherein the amount of primary cellulose is from 1 to 10 wt.% of the amount of the first solvent, (B) dissolving the amorphous cellulose phase, wherein the amorphous cellulose phase dissolves more preferentially than the crystalline cellulose phase, where the temperature at steps A and B is below 80 °C, (C) separation of dissolved amorphous cellulose from crystalline cellulose, where crystalline cellulose obtained in step B contains cellulose with type I structure according to RDA; microcrystalline or nanocrystalline cellulose-containing product P1 and nanocrystalline cellulose-containing product P2, obtained using the disclosed method, a mixture of microcrystalline or nanocrystalline cellulose and two versions of using microcellulose or nanocellulose as a coating material, filler or as a material for making cellulose moulded articles, as well as fibres or films used in production of packaging film, threads, fabrics or as raw material for production of carbon fibres.

EFFECT: simple method of a cellulose product having improved properties, particularly high crystallinity and purity.

30 cl, 5 dwg, 4 ex