Effect of Olive Leaf Powder on Structural, Thermal, Mechanical, and Antioxidant Properties of Polylactic Acid Based Biocomposite Films

ABSTRACT In the present study, polylactic acid films containing olive leaves with different particle sizes and different additive ratios were characterized in terms of structural, thermal, mechanical, and antioxidant properties. XRD and SEM analyses showed that PLA films with olive leaf powder generally have an amorphous structure, whereas films with low filler ratios and fine particles exhibit higher crystallinity. Not so surprisingly, neither filler amount nor mixing time are making a big difference in the crystallinity or morphology of the surface. In the context of DSC analysis, a maximum variation of 2°C in the glass transition temperature was observed. A comparable trend shift was observed between the T g (glass transition temperature for DMA) values in the DMA analysis and the T g (glass transition temperature for DSC) values in the DSC analysis. However, the change in the DMA analysis was more definitive. Antioxidant activity of the films was observed to increase with decreasing particle size of olive leaves added to polylactic acid and increasing additive ratio. Adding olive leaf powder to PLA and then looking at the effects on these aspects as mechanical, thermal, morphological, and antioxidant properties contributed to the evaluation of PLA as a potential additive for producing biodegradable polymers.