Effect of bonding on the structure and properties of nanocellulose films

In this study, cellulose nanofibers (CNF) were obtained by chemical pretreatment using a rubberwood substrate. Different forms of drying were used to prepare three CNF film variants. Each of the films was rehydrated and hot-pressed to introduce more hydrogen bonds, and the films were characterized in terms of density and porosity, micromorphology, and mechanical properties. The mechanical properties of the films improved substantially after rehydration and hot-press drying. The tensile strengths of the films increased to approximately two to three times that of the original CNF films. These results with micromorphological observations suggest that adjusting the water content during CNF drying can significantly improve the formation of 3D networks in the films, thus imparting higher hydrogen bonding content to the films and improving the mechanical properties of the substrates. This study provides a theoretical basis for the formation of high-strength materials through water molecule-induced assembly and broadens the application of biomass cellulose materials in emerging fields.