CELLULOSE NANOFIBERS MODIFIED WITH SULFURIC ACID ESTERIFICATION METHOD AND CELLULOSE NANOFIBRES PRODUCTION METHOD

FIELD: nanotechnology; cellulose industry. SUBSTANCE: present invention relates to modified sulfuric acid esterification method of cellulose nanofibres and to method of producing cellulose nanofibres. Cellulose nanofibres have average fiber diameter in range of 1??nm to 500??nm and hydroxylic groups modified by sulfuric acid esterification method on cellulose nanofibres surfaces， viscosity of 0.3??wt??% aqueous dispersion of cellulose nanofibres， at a measurement temperature of 25??°C， rpm of 2.6??rpm， is 500??mPa·s and more or in which the thixotropy index TI (2.6??rpm/26??rpm) of 0.3??wt??% aqueous dispersion of cellulose nanofibres modified by sulfuric acid esterification at 25??°C ranges from 3 to 30. Present invention also provides a method of producing cellulose nanofibres， which involves impregnating cellulose with a fibrillating solution containing dimethylsulphoxide， at least one carboxylic acid anhydride selected from acetic anhydride and propionic anhydride， and sulfuric acid， for fibrillation of cellulose， and a method of producing modified cellulose nanofibres， comprising modifying surfaces of cellulose nanofibres via esterification or urethane. EFFECT: invention enables to obtain cellulose nanofibres which are nanosized， have high degree of crystallinity and high aspect ratio， the method being a chemical method， for which there is no need for physical grinding， which is energy-saving and which can be executed in mild reaction conditions. 13 cl， 32 dwg， 4 tbl， 30 ex