Development and characterization of banana leaf powder reinforced PLA biocomposite films for sustainable packaging applications

ABSTRACT Biodegradable polymers reinforced with natural fillers are increasingly explored as sustainable alternatives to petroleum-based plastics for packaging applications. In this study, banana leaf powder (BLP), an abundant agricultural waste, was used as a reinforcement for polylactic acid (PLA) to fabricate biocomposite films via a solvent casting technique. BLP was incorporated at 0, 5, 10, 15, and 20 wt.%, and the resulting films were characterized for their mechanical, thermal, morphological, and water absorption properties. Fourier transform infrared spectroscopy (FTIR) revealed enhanced hydrogen bonding between the hydroxyl groups of BLP and the ester groups of PLA. Tensile testing (n = 5) showed that the 15 wt.% BLP/PLA composite achieved the highest tensile strength (71.5 ± 1.8 MPa) and elongation at break (8.1 ± 0.4%), representing an improvement of approximately 22% and 224%, respectively, compared to neat PLA. Thermogravimetric analysis indicated improved thermal stability, with the onset degradation temperature increasing from 290 °C for neat PLA to 325 °C for the 15 wt.% BLP composite. SEM analysis confirmed uniform filler dispersion at moderate BLP loadings, while higher contents led to particle agglomeration. Water absorption increased with BLP content due to the hydrophilic nature of the filler. Overall, the results demonstrate that BLP is an effective, low-cost, and sustainable reinforcement for PLA, with 15 wt.% BLP providing an optimal balance between mechanical performance and thermal stability for sustainable packaging applications.