A comparative study on the starch-based biocomposite films reinforced by nanocellulose prepared from different non-wood fibers

Nanocellulose was extracted from three kinds of non-wood fibers (bamboo, cotton linter, and sisal) by TEMPO-mediated oxidation and high pressure homogenization. Starch-based composite films containing different kinds of nanocellulose with different content (0–10 wt%) were prepared via solution casting method. The morphology and structure of the three kinds of nanocellulose and their respective effects on the composite films were compared by various characterizations. The impacts of nanocellulose content on the thermal stability and mechanical properties of the composite films were also evaluated. The study found that morphology and chemical composition of the nanocellulose obtained from different sources were almost the same, but there were slight differences in their size and crystallinity. Bamboo nanocellulose had the highest aspect ratio, which enabled it to provide the greatest reinforcing effects on the mechanical properties and barrier properties of the composite films. The addition of nanocellulose improved the mechanical properties of the films but reduced their elongation at break and thermal stability. This study paves the route for choosing the most effective non-wood nanocelluloe source and mixed ratio to produce food packaging with the best performance.