Effectiveness assessment of TiO <sub>2</sub> -Al <sub>2</sub> O <sub>3</sub> nano-mixture as a filler material for improvement of packaging performance of PLA nanocomposite films
Fatima Zohra Yakdoumi, Assia Siham Hadj‐Hamou
Abstract
Abstract The main objective of this study was to assess the effectiveness of TiO 2 -Al 2 O 3 nano-mixture used as filler in improving packaging films performance. Polylactic acid/titanium dioxide (PLA/TiO 2 ), polylactic acid/alumina (PLA/Al 2 O 3 ) and polylactic acid/TiO 2 -Al 2 O 3 (PLA/TiO 2 -Al 2 O 3 ) nanocomposite films were successfully prepared via melt mixing process and thoroughly characterized by FTIR spectroscopy, X-ray diffraction (XRD), UV–vis spectroscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The properties such as heat resistant, barrier, mechanical and antimicrobial properties, required for food packaging have also been investigated. As compared to the neat PLA film, the developed PLA nanocomposites have displayed superior properties particularly the PLA/ TiO 2 -Al 2 O 3 nanocomposite film. This resulted material has showed a 22 °C increase in its thermal stability versus 14 and 2 °C in the cases of PLA/TiO 2 and PLA/Al 2 O 3 respectively, and a 54% reduction of its water vapor permeability in comparison with 47% for PLA/TiO 2 and 39% for PLA/Al 2 O 3 . In addition, the PLA/TiO 2 -Al 2 O 3 had a significant enhancement of its mechanical properties. Its Young modulus increased by 102% unlike 23.60% for the PLA/TiO 2 and 44.66% for the PLA/Al 2 O 3 . It was also noticed that this nanocomposite film demonstrated stronger antibacterial activity than the two others. The bacterial growth inhibition effect of TiO 2 -Al 2 O 3 nano-mixture against Pseudomonas aeruginosa and Escherichia coli bacteria was more effective than that of its two constituents.