To prepare the PLLA films, 10 grams of PLLA granules were dissolved in 50 grams of chloroform. The solution was stirred at 200 RPM for 4 hours at room temperature until fully dissolved. To minimize bubble formation, the solution was refrigerated overnight at 4°C. The cold PLLA solution was poured into a glass Petri dish and allowed to air dry at room temperature for 4 hours. Once dried, the PLLA film was carefully removed from the Petri dish and cut into square pieces measuring 50 × 50 mm. The pre-cut films were subjected to uniaxial stretching to achieve draw ratios between 50% and 100%. The uniaxial stretching of the films was performed using a Zwick/Roell Z050 tensile testing machine. The initial speed was set to 50 mm/min, with a pre-load of 0.1 MPa applied at a speed of 5 mm/min. The tensile modulus measurement was conducted at a speed of 1 mm/min, followed by a test speed of 20 mm/min for the stretching process. The uniaxial stretching was performed at room temperature. The films were fixed at their strained length and subjected to heat treatment for 8 hours at 80°C. Upon completion of the heat treatment, they were rapidly quenched in an ice bath for 7 hours to stabilize their structure.