امیر رستمی

The main objective of this work was to compare the different modes of addition of metal oxide on the desired properties of poly(lactic acid) (PLA) as matrix. In this regard, firstly, zinc oxide nanorods (ZnO) and hybrid nanoparticles of ZnO-titanium dioxide (TiO2) (called as TZO nano-hybrid) were synthesized by a simple hydrothermal process and were characterized by means of FE-SEM, FTIR, and XRD techniques. Afterward, PLA nanocomposites including various amounts of synthesized nanoparticles were fabricated. The results demonstrated a proper nanoparticles dispersion and distribution state in the case of low percentages of inclusion and an elevated aggregation for the higher percentages. But, excellent dispersion with the lowest amount of aggregation was observed for TZO nano-hybrid in the PLA matrix, which directly affected the physical and mechanical properties and also anti-bacterial performance of PLA. For example, the tensile strength and Young's modulus of PLA, by incorporation of 7 wt% TZO, increased from 42.5 to 44 MPa and 1325.3 to 1917.5 MPa, respectively. It was also found that the type of morphology of nanoparticles plays a key role in the improvement of these properties. The results of the tests investigated in this study showed that fabrication of TZO nano-hybrid and its dispersion in the PLA matrix gave the best desirable properties in this polymer compared to the other two dispersion modes (single-incorporation and simultaneously-incorporation nanocomposites). These novel nanocomposite films can be considered as a good candidate for the packaging industry.