PLA based biocomposites reinforced with Posidonia oceanica leaves

Biocomposites can valorize some natural products related to natural processes or crop and waste industries. In this work, leaves of Posidonia oceanica (PO), dominant sea grass in the Mediterranean Sea, were used to prepare PLA based biocomposites. Materials were prepared by melt mixing PLA with PO as filler. The morphology as well as the mechanical and thermal properties of PLA/PO composites were evaluated and related with the influence of the content and size of PO. Moreover, the experimental elastic moduli of the biocomposites was modelled employing the Halpin-Tsai (HT) model. Furthermore, in order to take into consideration the high porosity of PO leaves, the HT parameters related to the density of PO were evaluated by estimating the % of PO filled by PLA. The results highlighted that the use of PO leaves as filler influenced all the investigated properties. In particular, by increasing the PO content, both tensile and flexural moduli increased. While, on the contrary, both tensile and flexural strengths of the biocomposites decreased if compared with neat PLA. Finally, the method to determine the parameters for the HT model was found to be able to give a good evaluation of tensile modulus of the composites, for all the filler content and size.