The mechanical properties were determined using a universal test machine according to the ASTM standard method D882 (ASTM, 2001). Conditioned samples (2.5 cm x 10 cm) were mounted in the film-extension grips of the testing machine and stretched at 50 mm/min until breaking. The tensile strength (TS), the elastic modulus (EM), and the elongation at break (ε) of the films were determined from the stressstrain curves, estimated from the force-distance data obtained for different films. The conditioned film thickness was measured using a Palmer digital micrometer at six random positions around the film.