Sustainable synthesis and characterization of bioplastic films from whole banana peel: a comparative study on plasticizer-hydrolyzer ratios

The present research focuses on the synthesis of bioplastic film from raw banana peels. This synthesis approach differs from conventional bioplastics by utilizing whole banana peel waste instead of extracted starch. In preparation for bioplastic film (BPF), acetic acid and glycerol were used as hydrolyzer and plasticizer respectively with different proportions such as 1:1 (BPF-I), 1:2 (BPF-II) and 3:8 (BPF-III). The synthesized bioplastic films were analyzed using multiple techniques to investigate their physicochemical properties and biodegradability. The surface morphology of bioplastic films was evaluated by using scanning electron microscopy (SEM). Fourier Transform Infrared (FTIR) spectroscopy and RAMAN spectroscopy were utilized to investigate the chemical and intermolecular interaction of fabricated BPF. The contact angles were measured to be 42.20̊ ± 1.5̊, 58.20̊ ± 2.4̊ and 53.30̊ ± 1.7̊ for prepared BPF respectively. Stress-strain analysis was conducted to assess the mechanical stability of BPF. Mechanical analysis showed that BPF-II had the highest tensile strength (0.42 ± 0.02 MPa) and Young’s modulus (0.047 ± 0.02 MPa), demonstrating optimal plasticization. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were used to assess the thermal decomposition of the fabricated bioplastic films. The swelling and uptake capacity of developed BPF were analyzed in distilled water. BPF-I, BPF-II, and BPF-III exhibited 86 ± 3.75%, 91 ± 4.10%, and 96 ± 3.40% degradation in soil over 60 days, demonstrating their excellent degradability. Optimizing the plasticizer-to-hydrolyzer ratio enhanced mechanical strength, thermal stability and biodegradability, with BPF-II emerging as the most viable sample for sustainable packaging and environmental applications.