Carboxyethylated nanocellulose is a kind of nanocellulose obtained by carboxyethylation pretreatment combined with mechanical fibrillation, which has unique properties and broad application prospects. The carboxyethylation pretreatment technology has wide applicability of raw materials, low cost and saves mechanical energy consumption. In this paper, carboxyethylated nanocellulose was prepared and applied in porous nanopaper, high filler paper, barrier packaging paper, and conductive paper. The results showed that, nanocellulose with different carboxyethyl content could be obtained by controlling the chemical dosage. Carboxyethylated nanocellulose with carboxyethyl content of about 1 mmol/g is suitable for preparing nanopaper by coating method, which is compact and has high strength. The pore structure of the nanopaper can be enriched and regulated by using organic solvent replacement, different drying methods and adding cationic additives. The type of raw materials and grinding degree also affect the structure of nanopaper. The porosity of the final obtained nanopapers can be controlled between 20% and 90%. In addition, high filler papers with a filler content more than 50% was prepared using Carboxyethylated nanocellulose and inorganic filler by coating process. Due to the contribution of carboxyethylated nanocellulose to the strength properties, the composite paper has good mechanical properties even when the filler content is as high as 70%. The folding resistance and flexibility of the composite paper can be improved by adding plasticizer. Furthermore, carboxyethylated nanocellulose can be coated on the surface of paperboard to improve its oxygen and water resistance. It can also form a double coating with a degradable polymer to improve the Cobb value, oil resistance, grease resistance and leakage of papers, which can replace non-biodegradable PE coated paper. Finally, carboxyethylated nanocellulose/graphene/polypyrrole conductive composite papers were prepared by physical mixing and in-situ adsorption polymerization. The abundant hydrogen bonds of carboxyethylated nanocellulose played an important role in giving flexibility and strength to the conductive papers. Therefore, carboxyethylated nanocellulose has a wide range of potential applications in the field of papermaking due to its unique properties.

Carboxyethylated nanocellulose; Porous nanopaper; High filler paper; Barrier packaging paper; Conductive paper