2.4.5. Mechanical properties The mechanical properties of the composite films were determined at 22◦C and 30% RH with an Instron 5565 Universal Testing machine (Instron, Canton, MA, USA) according to ASTM standard method D882 [34]. Films were cut in rectangular strips of 50 mm long and 6.35 mm wide. The films were fixed with an initial grip separation of 25 mm and stretched at an extension speed of 0.8