Preparation and characterization of polyvinyl alcohol/polylactic acid/titanium dioxide nanocomposite films enhanced by γ-irradiation and its antibacterial activity

Synthesis of antimicrobial films for packaging applications is eminent fields of research. This study describes preparation of biodegradable Poly (PVA/PLA/TiO2) nanocomposite films was carried out by blending polyvinyl alcohol (PVA) and polylactic acid (PLA) doped with titanium dioxide (TiO2) nanoparticles using solution casting method and then irradiated by gamma-irradiation. The properties of the films were characterized by FT-IR, XRD, FE-SEM, TEM, TGA, and mechanical tests. The addition of TiO2 nanoparticles (0.8 wt%) explored considerable effects on thermal stability of the films. Results of FE-SEM and TEM illustrated quite uniformly dispersion of TiO2 nanoparticles with average size of 17.5 nm. The effect of gamma-irradiation on nanocomposite films showed enhanced water resistance property and water vapor transmission rate. The water resistance property was achieved using PVA/PLA composition ratio (2/1). The antibacterial activity was evaluated against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) bacteria. Poly(PVA/PLA/TiO2) nanocomposite film irradiated at 20 kGy displayed improved antibacterial activity and was selected for soil burial biodegradation tests. The biodegradation rate increased rapidly in the initial 12 weeks with significant changed morphology. The enhanced antibacterial efficiency and biodegradation property of the nanocomposite films suggest their possible use for development of packaging materials with low environmental impact.

Automated summary

This study successfully synthesized antimicrobial films for packaging applications. Biodegradable Poly (PVA/PLA/TiO2) nanocomposite films were prepared by blending PVA and PLA with TiO2 nanoparticles and irradiated by gamma-irradiation. The addition of TiO2 nanoparticles improved the thermal stability and antibacterial activity of the films, while gamma-irradiation enhanced their water resistance and biodegradation property.