Mechanical and Permeability Properties of Thermoplastic Starch Composites Reinforced with Cellulose Nanofiber for Packaging Applications

Abstract

In this study, a facile, ecofriendly nanocomposite based on glycerol-plasticized thermoplastic potato starch (TPS) containing 0-4 wt.% cellulose nanofiber (CNF) from pineapple leaf was prepared by the solution casting technique. The nanocomposite films showed better mechanical properties compared to neat film. The tensile properties were fit with theoretical predictions. Tensile strength increased with CNF loading and reached up to 4.682 MPa (TPS+3 wt.% CNF) from 1.58 MPa (neat TPS), an improvement of ~196% over the neat polymer. The addition of cellulose nanofiber improved the barrier properties of films by creating a tortuous path for penetrant molecules. Gas transport behavior of CNF-based TPS nanocomposite films was explored using O2 gas. A 56% decrease (relative to neat TPS) in oxygen permeability of the nanocomposite membranes was achieved by adding only 3 wt.% CNF. The oxygen permeability data were fit with two theoretical models