Preparation of nanocellulose from bagasse and its application in chitosan composite films

Cellulose nanocrystals (CNC) are promising for preparing composite materials for food packaging and preservation; however, few studies have utilized nanocellulose from sugarcane bagasse for developing composite membranes. In this study, CNC from bagasse was prepared, CNC/chitosan (CS)/glycerol composite membranes were obtained by the mixing and extensional flow method, and the formulations were optimized using single-factor and orthogonal tests to investigate the effects of CNC, CS and glycerol on the mechanical properties, barrier properties, structure and thermal stability of the composite films. The composite film prepared showed better performance at CNC, CS and glycerol concentrations of 1, 1.5 and 0.75%, respectively. Compared with those of the CS membrane, the barrier performance was improved (p < 0.05). The morphology of CNC and CNC/CS composite films was observed by scanning electron microscopy. The structure was characterized by Fourier transform infrared spectroscopy and X-ray diffraction, and thermal stability was analysed by thermogravimetric analysis. Hydrogen bonding between nanocellulose and CS enhanced the cohesion of the composite film. The newly prepared CNC/CS composite film showed good mechanical properties, barrier properties and stability. It has potential applications in the food packaging industry to extend the shelf life of food and is energy-saving and environmentally friendly.