Effect of nano-cellulosic fiber on mechanical and barrier properties of polylactic acid (PLA) green nanocomposite film

Most of the packaging products are made up of non-biodegradable materials resulting in environmental pollution, so the materials derived from natural resources such as polylactic acid and cellulose nanofibers have been strongly advocated as potential material for packaging application. In this work, optically transparent green nanocomposite films were prepared by the incorporation of cellulose nanofibers (1, 3, 5 wt%) into the polylactic acid (PLA) matrix using a cost-effective solvent casting method. The resulting green nanocomposite films were evaluated for morphology, structural and, thermal properties by Scanning electron microscopy (SEM), x-ray diffraction (XRD), and Thermogravimetric analysis (TGA/DTG). The Cellulose nanofibers (CNFs) prepared by directly treating the jute fiber with HNO3-NaNO2 mixture resulted in CNFs diameter of 4-6 nm and length of several micrometers. SEM results revealed the uniform dispersion of CNFs into the PLA matrix. The incorporation of CNFs improved the physical properties, such as mechanical and barrier properties (Water vapor transmission rate and oxygen permeability) of the prepared nanocomposite films. Specifically, a higher loading of 5 wt% of CNFs in the PLA matrix enhanced the barrier and mechanical properties of the nanocomposite film compared to those of the pristine PLA films. Furthermore, the prepared nanocomposite films were optically transparent and thermally stable. These results demonstrate the use of HNO3-NaNO2 Oxidized CNFs in PLA matrix that makes it possible to produce nanocomposite film that has potential in packaging application.