SULFURIC ACID ESTERIFICATION MODIFIED CELLULOSE NANOFIBERS AND METHOD FOR PRODUCING CELLULOSE NANOFIBERS

摘要

The present invention provides novel sulfate ester modified cellulose nanofibers. The cellulose nanofibers are cellulose nanofibers that have an average fiber diameter in the range of 1 nm to 500 nm, and that have sulfate ester modified hydroxyl groups on surfaces of the cellulose nanofibers. The present invention also provides a method of producing cellulose nanofibers that are nanosized, that have a high crystallinity degree, and that have large aspect ratios, the method being a chemical method that does not require any physical pulverization, that is energy-saving, and that can be performed under mild reaction conditions. The present invention also provides a method of producing modified cellulose nanofibers including modifying the surfaces of the cellulose nanofibers through esterification or urethanization. A method of producing cellulose nanofibers of the present invention includes impregnating cellulose with a fibrillation solution containing dimethylsulfoxide, at least one carboxylic acid anhydride selected from acetic anhydride and propionic anhydride, and sulfuric acid to fibrillate the cellulose.