Investigation of mechanical, barrier, and antibacterial properties of PBST composites strengthened with KH-570 silane-coated MgO/Ag nanoparticles

Abstract

MgO/Ag nanoparticles (NPs) have been surface modified with the silane coupling agent KH-570. The modified NPs (KMA) were added to poly (butylene succinate-co-terephthalate) (PBST) to prepare the K-PMA composite films. The modification improved the compatibility between MgO/Ag NPs and PBST matrix. The study comprehensively investigated the effects of modified MgO/Ag NPs on the mechanical, antibacterial, and preservation properties of bio-nanocomposite films. The incorporation of NPs substantially improved the mechanical and barrier properties of the PBST matrix. The composite films exhibited the best overall performance when the nanoparticle content is 3 %. In particular, the elongation at break, tensile strength, and water vapor permeability (WVP) were 794.67 %, 32.20 MPa, and 1.53 × 10⁻¹¹ g·m/m²·s·Pa, respectively. Furthermore, the K-PMA-3 composite film exhibited excellent antibacterial properties and food preservation performance. The inhibition rates against Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), and Salmonella paratyphi B (S. paratyphi B) were all over 98 %. After 6 days of preservation experiments, the mass loss of cherry tomatoes wrapped with K-PMA-3 film was only 5.9 %, which was only 45 % of the mass loss of cherry tomatoes wrapped with PMA-3 film. The results showed that the prepared biofilms have a great potential to be used as food packaging films.