High-Barrier Oxidized Cellulose Nanofibril/Chitosan Coating for Functional Food Packaging Materials

With the continuous introduction of plastic restriction policies by the government and the continuous enhancement of people’s awareness of environmental protection, the demand for food packaging materials has also continued to increase, and the research and development of biodegradable green packaging materials has become the frontier research direction in the field of food packaging materials. In this study, nanocellulose-based coating solution with high barrier properties was prepared from oxidized cellulose nanofibrils (OCNFs) via sodium periodate and compounded with chitosan solution (CTS) and then coated on the substrate paper. Experiments have found that when the mass fraction of the OCNF in the OCNF/CTS coating solution is 0.5%, the coated paper exhibits the optimum comprehensive performance. The oxygen transmission rate of the OCNF/CTS-coated paper dropped to 1.732 × 10^–11 cm³·cm/cm²·s·Pa, and the water vapor transmission rate reduced to 2.236 × 10^–12 g·cm/cm²·s·Pa. This is due to the fact that the OCNF cross-linking with CTS improves the compactness of the paper surface layer, which in turn enhances its barrier. These findings suggested that the OCNF/CTS-coated paper has great potential and prospect in the application of food packaging materials, which provide a possible positive example of barrier coating in the packaging field.