Development of Antimicrobial Packaging Film Made from Poly(Lactic Acid) Incorporating Titanium Dioxide and Silver Nanoparticles

Polylactide (PLA)nano-TiO2 and PLA/nano-TiO2/nano-Ag blends films were prepared by a solvent volatilization method. Compared to pure PLA film, the nano-blend films have low water vapor permeability (WVP) and a poor transparency. With the increase of the NPs in the PLA, the tensile strength (TS) and elastic modulus (EM) decreased, while the elongation at break (E) increased. SEM analysis indicated a rougher cross-section of the nano-blend films. According to the FTIR analysis, no new chemical bonds were formed in the nano-blend films. By using DSC to examine the crystallization and melting beha(v)ior, the result shows that the NPs have no effect on the glass transition (T-g) and melting temperature (T-m), but they caused an increase on the cold crystallization (T-c) and crystallinity (X-c). TGA results show that the addition of nanoparticles significantly improved the thermal stability. The PLA nano-blend films show a good antimicrobial activity against. E. coli and Listeria monocytogenes. Most important, we carried out migration tests, and verified that the release of NPs from the nano-blend films was within the standard limits.