Simultaneous Effect of Wood Flour and Starch‐Based Compound on the Mechanical Behavior of Polylactic Acid (PLA)

ABSTRACT In this research, we investigated the effects of wood flour and starch‐based compositions on the mechanical behavior of polylactic acid. Composite samples were created by mixing polylactic acid, starch‐based compositions, and wood flour using extrusion along with compression molding methods. The mechanical behavior of PLA composites has been evaluated using tensile, compression, and drop weight tests. In order to find out the dispersion of filler particles inside the PLA, microscopic evaluation has been performed by scanning electron microscope. The results of SEM micrographs showed that the wood flour particles within the PLA dispersed uniformly up to 30 wt%. However, in samples with a 30% wood flour content, voids were observed in the morphology. The results of the tensile test showed that the tensile strength of samples containing 40% and 50% polylactic acid, with the addition of 20% wood flour, was higher than that of the other samples in comparison to other compounds. The compression test results reveal that the presence of wood fibers causes cracks to develop along the direction of the applied force. As the pressure force increases, these cracks progressively expand and join together, ultimately resulting in sample failure. In addition, the drop weight test results demonstrate that the significant impact of wood flour is attributed to its role in creating porosity.