Development and evaluation of deacetylated konjac glucomannan based films incorporated with cellulose nanofibers and alumina nanoparticles

The aim of this study is to investigate the effects of different cellulose nanofibers (CNF, 0–20% w/w) and aluminum oxide nanoparticles (Al₂O₃ NPs, 0–4% w/w) concentrations on the properties of deacetylated konjac glucomannan (DKGM) base film, as well as the protective performance of DKGM-based composite film on wood. The addition of CNF primarily improves the mechanical properties of the film. Compared to the KGM base film, the DKGM/CNF composite base film (DKC) exhibits excellent tensile strength and elongation at break, with increases of 44.39 MPa and 19.87%, respectively. After application to the wood surface, the glossiness of the wood increased by 43.48%, and the moisture absorption dimensional change rates reached 0.07% (radial) and 0.11% (tangential), while the moisture absorption coefficients decreased to 0.008 (radial) and 0.019 (tangential). The addition of Al₂O₃ NPs primarily improves the film’s resistance to ultraviolet light and water. Compared to the DKGM base film, the water contact angle, water solubility, and water vapor barrier performance of the DKGM/ Al₂O₃ composite base film (DKA) significantly improved. When applied to the wood surface, the wood wear resistance and aging resistance increased by 62% and 69.67%, respectively. Therefore, DKGM base films doped with CNF and Al₂O₃ NPs have broad development prospects in the field of wood protection.