Extraction and fabrication of starch-based reinforced bioplastics from <i>potato</i> : Circular and sustainability aspects

Biodegradable bioplastic films have emerged as promising alternatives to conventional plastics due to their environmental benefits. However, starch-based bioplastics often exhibit poor mechanical properties, which limit their practical applications. The incorporation of reinforcing agents can enhance these properties while promoting sustainability. This study aims to investigate the mechanical properties and biodegradability of starch-based bioplastic films reinforced with organic waste fillers, including eggshell, sawdust, and biochar. The films were fabricated from isolated potato starch, glycerol, vinegar, and water using a starch:glycerol:vinegar:water weight ratio of 1:0.23:0.23:10, with 10% weight by weight (w/w) filler reinforcement. Mechanical properties were evaluated using a universal testing machine (UTM). Functional groups were analyzed by Fourier Transform Infrared (FTIR) spectroscopy, and biodegradability was assessed through soil burial tests. Sawdust reinforced films (SD) exhibited a significantly higher tensile strength of 5.7 ± 0.510 MPa and a Young’s modulus of 130 ± 2.050 MPa compared with the control pure starch film (PS), which showed 1.9 ± 0.352 MPa tensile strength and 13.7 ± 0.456 MPa Young’s modulus. FTIR spectra confirmed the presence of functional groups conducive to biodegradation. Soil burial tests revealed up to 36% mass loss within 15 days, indicating substantial biodegradability. The integration of organic waste fillers, particularly sawdust, significantly enhances the mechanical and biodegradation properties of starch-based bioplastics. These findings support the potential of organic waste reinforcements for developing sustainable and biodegradable plastic alternatives.