PLA Nanocomposites Reinforced with Cellulose Nanocrystals from Posidonia oceanica and ZnO Nanoparticles for Packaging Application

Poly(lactic acid) (PLA) based nanocomposites reinforced with 1 wt% of surfactant-modified cellulose nanocrystals (s-CNC) extracted from Posidonia oceanica plant waste and zinc oxide nanoparticles (ZnO NPs) at different concentrations (0.1 and 0.5 wt%) were prepared by solvent casting process. Their thermal, morphological, optical, mechanical and water vapor permeability properties were investigated. Tensile testing showed increased values for strength and deformation at break in PLA based formulations reinforced with s-CNC and ZnO NPs as a consequence of better nanofiller dispersion compared to binary films reinforced only with ZnO NPs. Moreover, the effect of s-CNC and ZnO NPs provoked an improvement of barrier properties, highlighting the synergic ability of nanofillers to increase the tortuous path of gas molecules, reducing the water vapor permeability coefficients, a property of fundamental importance in food packaging applications. Finally, antimicrobial activity was evaluated using two bacterial strains, Escherichia coli and Listeria innocua.