Effect of different red palm oil volume on characteristics and degradation of polylactic acid/zinc oxide film

Abstract

Abstract PLA/ZnO combination caused agglomeration, especially at a high concentration of ZnO. This condition improved by adding a plasticizer to smoothen the incorporation of ZnO into PLA. The work’s objective was to study the changes in polylactic acid/zinc oxide (PLA/ZnO) film’s properties incorporated with red palm oil (RPO) that acted as a plasticizer. The films were prepared using the solvent casting method. RPO’s impact as a plasticizer was determined on the film’s thickness, moisture content, functional group, mechanical properties, and solubility. More RPO increased the thickness because of the formation of more free volume in the polymer matrix. Otherwise, the moisture content has shown a different trend, which decreased with more RPO content. Fourier transform infrared spectroscopy proved that interaction occurred between each material in this film by sharpening the peak representing the ester group, C = O stretching bonds, 1365 cm−1 (C-H bending), and 1216 cm−1 (C-O stretching). The highest tensile strength obtained by PLA/ZnO/0.25RPO, showing the lowest performance in elongation at break. ZnO increased the solubility of PLA film, but the presence of RPO proportionally reduced the solubility. These results counsel that the PLA/ZnO/RPO films could be applied as an alternative to manufacture film packaging that needs high tensile strength and low elongation at break. Further study should be conducted for a range of one until 25 weight % of RPO over 100% PLA to determine the optimum formulation.