Preparation and Properties of Biocomposite Films Based on Poly(vinyl alcohol) Incorporated with Eggshell Powder as a Biological Filler

Abstract

Biocomposites of poly(vinyl alcohol) (PVA) incorporated with eggshell powder (ESP) were prepared by solution blending and casting into films. The effects of ESP content (0–50 wt% of dry PVA basis) on structure and properties of the resultant PVA/ESP composite films were systematically evaluated. Fourier transform infrared spectroscopy and scanning electron microscopy suggested a strong adhesion and the well-dispersion of ESP particles in the PVA matrix due to the hydrogen-bonding interactions. The incorporation of opaque, hydrophobic and stable ESP in the composite films could consequently decreased their transparency and hydrophilicity while improving their thermal stability. Optimal ESP content in the composite films was found to be 30 wt% in terms of their mechanical and water vapor barrier properties, showing a tensile strength of 38.78 MPa, elongation at break of 165.9%, and water vapor permeability of 1.229 × 10–12 g cm/cm2 s Pa, respectively. However, overloading of ESP in the composite films might produce some aggregations and thus have negative effects on their performance. These results indicated that ESP was an excellent biological filler for PVA to prepare composite films with improved properties, which might hold the potential as biodegradable materials for packaging applications.