A kind of method for preparing nanometer microcrystalline cellulose cnc

Abstract

Cellulose nanocrystals (CNC) are prepared from bleached sulphate hardwood pulp through a hydrochloric acid hydrothermal process, the hydrochloric acid has relatively weak acidity so that the hydrochloric acid can slowly remove amorphous zones while avoiding destroy on the degree of crystallinity as far as possible in a cellulose nanocrystal preparation process, thus preparing a product having a high yield and uniform dimension. In addition, the cellulose nanocrystals prepared by utilizing the hydrochloric acid contain a large amount of hydroxyl which is hydrophilic and high in polarity, and anobjective of improving flocculation can be achieved through adding CTAB (cetyltrimethylammonium bromide) to improve the number of surface charges and to increase steric hindrance. The method is simple and feasible, effectively improves defects of traditional cellulose nanocrystal preparation through hydrochloric acid methods, and is of great significance for promotion of industrial preparation ofcellulose nanocrystals.

Description

technical field [0001] The invention belongs to the field of pulp and papermaking, and in particular relates to a method for preparing nano-microcrystalline cellulose CNC. Background technique [0002] Nanocrystalline cellulose (CNC) has high strength and modulus, large specific surface area, low specific heat coefficient, high aspect ratio, biodegradability, hydrophilic and lipophilic properties, these unique structures and The performance makes nanocellulose specific in physics and chemistry, and can significantly change the mechanical, electrical, optical, and even superconductivity and insulation properties of materials. Therefore, nanocellulose is widely used in construction, papermaking, food, automobiles, electronic products, biomaterials, cosmetics, medicine, ultra-precision instruments, aerospace, military and other fields. At present, most of the methods for preparing nanocrystalline cellulose are prepared by hydrolysis of sulfuric acid, but due to the strong acid...

AI Technical Summary

Problems solved by technology

At present, most of the methods for preparing nanocrystalline cellulose are prepared by hydrolysis of sulfuric acid, but due to the strong acidity of sulfuric acid, the reaction is more violent, and the conditions for preparing nanocrystalline cellulose (SCNC) with sulfuric acid are relatively harsh and the yield is low. Poor stability, which affects subsequent further applications such as casting molds, double helix self-assembly, etc.

Images