The morphological and physico-mechanical properties of wood plastic composite made of polylactic acid polymer

This study aims to fabricate an eco-friendly wood plastic composite with poly (lactic acid) biodegradable matrix reinforced by wood flour and pulp fibers. Polylactic acid (PLA) samples were compared to the samples made from one of the most commonly used synthetic plastics, i.e. low density polyethylene to evaluate the results of this study. Besides, in order to achieve the best characteristics of the new composite, some effective factors such as the mixing percentage of the filler and matrix in four levels and the shape of the wood material in two levels of wood flour and pulp fibers were used as variables. Samples made of PLA and low density polyethylene were fabricated by flat press and by injection molding, respectively, according to ASTM standard. In this work, in addition to test the physical and mechanical properties, the morphological properties of the new product were studied by electron scanning microscopy. According to the results, the mechanical properties of all samples made of low density polyethylene and poly lactic acid increased with increasing content of paper fibers and wood flour and the highest mechanical strength was observed for samples containing low density polyethylene. The results of physical properties also showed that in all specimens, with a decrease in the content of wood flour and paper fibers, water absorption and thickness swelling were improved. In addition, samples made of low density polyethylene showed better physical properties than samples containing PLA polymer. Finally, by reviewing the results of this study and comparing the microscopic images of the samples, it can be concluded that the best mechanical and physical resistance are related to specimens made with low density polyethylene and wood flour.