Reactive extrusion of sustainably sourced polymer blends based on Poly (lactic acid) and Polyamide 11: improvement of melt strength, toughness and enlargement of blown processability . Fatma WALHA1,3, Khalid LAMNAWAR2,4, Abderrahim MAAZOUZ2,3,5 Mohamed JAZIRI1 1) Laboratoire Electrochimie et Environnement, ENIS, Université de Sfax 3038 Sfax, Tunisie 2) Université de Lyon, INSA-LYON, F-69361 Lyon, France 3) UMR 5223, Ingénierie des Matériaux Polymères IMP, CNRS, INSA Lyon, F-69621 Villeurbanne, France 4) UMR 5259, Laboratoire de Mécanique des Contacts et des Structures LaMCoS, CNRS, INSA Lyon, F69621, Villeurbanne, France 5) Hassan II Academy of Science and Technology, 10 100 Rabat, Morocco The objective of this study was to gain a true understanding of the effect of the composition and compatibilization on the properties of entirely sustainably sourced polymer blends based on polylactide (PLA) and polyamide 11 (PA11). The main focus of this study is to overcome the shortcomings of PLA including its thermal instability, poor shear and low elongation viscosities in order to enhance its processability and to expand its application area. Polymer blends were prepared with various compositions of PA11 and various amounts of a chain extender containing reactive epoxy functions. Results showed that a “self compatibilization” between PLA and PA11 chains can occur but it was found to be insufficient, contrary to recent work reported in the literature. The role of Joncryl as a compatibilizer for the PLA/PA11 system has been demonstrated by the significant decrease of particle size and interfacial tension as well as the improvement of ductile properties. Mechanical as well thermo-mechanical properties were also investigated. Experiment results revealed a significant improvement of melt-strength and toughness according to the in situ formation of PLA-co-PA11 copolymers in the presence of the glycidyl methacrylate functions. Based on the improved shear and elongational rheological properties, a great enlargement of the blowing processing window of PLA blends was demonstrated (i.e by the study of blow and tack up ratios (BUR and TUR) ). Besides, the incorporation of PA1