This project, having taken place in the Centre Català del Plàstic, is focused on the production and characterization of biobased blends of poly (lactic acid) (Ingeo 4032D) modified with a multi-epoxide agent (Joncryl ADR 4400) and a partially biobased polyamide (Zytel RS LC3060 NC010). The main goal of the project, being to obtain a blend with enhanced thermal and mechanical properties compared to its pure components. It consists on a previous study in a lab scale of the development of blends for a pilot plant production, for that, the first step of the project consisted on the determination of the optimal content of multiepoxide agent and the analysis of the effect of using antioxidants. With this in mind, different grades of PLAREx were produced by using an internal mixer with blending parameters similar to those of extrusion processes and the ability of the materials to maintain a certain thermal stability to avoid degradation of its thermomechanical properties during mixing at high temperatures (235 °C) was analysed. Next, once the appropriate grade of chain extender was defined, the thermal stability of the different PLAREx/PA blends was evaluated by changing the composition from the 10 to the 50 wt.% of PA to determine the optimal mixing time. To compare with, the raw materials and PLA/PA blends were also processed under the same conditions. Once specified the suitable mixing time, the final blends were produced, and plates were obtained from them by compression moulding in a press. Following, these plates were morphologically, thermally and mechanically characterised. The morphological analysis showed a typical structure of immiscible polymer blends, with one phase conforming the matrix (PLA) and the other dispersed into the matrix as droplets or fibrils depending on its own composition (PA). An effect of the addition of a multi-epoxide agent on the morphology was also noticed, reducing the size of the PA droplets and moving the composition at which phase inversion takes place to higher PA contents. In addition, the different thermal transitions and their evolution with the PA content showing the typical behaviour of immiscible polymer blends as well. Interferences between both polymers were observed in terms of the crystallisation processes taking place. Finally, the tensile test results demonstrate a transition from a fragile to a ductile behaviour by increasing the PA amount of the blend.

Incoming