Antioxidant and antifungal effects of eugenol incorporated in bionanocomposites of poly(3-hydroxybutyrate)-thermoplastic starch

For this purpose, poly(3-hydroxybutyrate) (PHB)-thermoplastic starch (TPS)/organically modified montmorillonite (OMMT)/eugenol bionanocomposites were prepared by melt blending. Morphological, thermal and mechanical properties were determined by comparing the influence of the eugenol and clay on the PHB-TPS blend and PHB. The X-ray diffraction (XRD) diffractograms and Transmission electron microscopy (TEM) micrographs indicated that the morphology of the bionanocomposites were intercalated-exfoliated. The presence of additives did not affect the decomposition temperature of PHB, but if the melting temperature decreased by approximately 10 °C, the degree of crystallinity increased with respect to PHB. Tensile test indicated that the elastic modulus decreased by 25% for the PHB-TPS (65:35) blend, while for the PHB-TPS (65:35)/OMMT bionanocompuestos increased by 12%, compare to pure PHB. Finally, bionanocomposites with eugenol exhibited antifungal activity against Botritys cinerea and antioxidant activity, as indicated by high percentages of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical removal. This study showed that bionanocomposites with eugenol could be used as food packaging materials.