Preparation of Degradable Sago Starch Film Incorporated with Zinc Oxide (ZnO) Nanoparticles for Enhanced Chemical Barrier and Mechanical Properties

Abstract

The main objective of this study is to reinforce the mechanical strength and water resistance abilities of sago starch biopolymer by incorporating ZnO nanofillers. The biopolymer based nanocomposite films were cast utilizing different weight percentages of ZnO nanofillers (0, 1, 3 or 5 wt%) in sago starch matrix through solution casting technique. Uniform dispersing of ZnO nanofillers throughout the sago starch matrix was achieved by sonication and also to prevent the formation of ZnO nanoparticles aggregates. This was to further reinforce the chemical barrier properties of the film The results illustrated that with the increase of loading of ZnO nanoparticles from 0 to 5 wt%, the tensile strength and elastic modulus improved from 0.180 to 0.980 MPa and from 3.410 to 6.401 MPa respectively for the films, attributing to the high surface to volume ratios, the high mechanical strength of ZnO nanoparticles and the strong nanofiller-matrix interfacial adhesion. The elongation at break also enhanced owing to the slippage of ZnO nanofillers and the oriented sago starch polymer which activated the shear flow of the sago starch polymer. Sago starch nanocomposites with ZnO loadings varied from 0 to 5 wt% demonstrated decreased water vapour permeability from 4.992 × 10−10 g m−1 s−1 Pa−1 to 2.723 × 10−10 g m−1 s−1 Pa−1.