Plasticized and Nanofilled Poly(lactic acid)-Based Cast Films: Effect of Plasticizer and Organoclay on Processability and Final Properties

PLA-based nanocomposites filled with the commercial organomodified montmorillonite Dellite 43B (D43B) and containing acetyl tri-n-butyl citrate (ATBC) as plasticizer were prepared by extrusion in a pilot-scale twin-screw extruder and melt casted into flexible films. A preliminary investigation was carried out in a laboratory batch mixer by varying blending conditions and addition procedures of the components. Indeed, the method of addition of ATBC and D43B considerably affected thermo-mechanical properties and morphology of the resultant nanocomposites. The simultaneous introduction of both ATBC and D43B during the extrusion process allowed producing clearly exfoliated nanocomposite materials with modulated mechanical and thermal properties. Moreover, rheological results, obtained during melt extrusion, assessed the processability of nanofilled-plasticized PLA, making this simple procedure interesting in view of the industrial production of nanostructured biomaterials based on plasticized PLA.