Sustainable starch-based bioplastics reinforced with carob filler: characterization and biodegradability assessments

Starch-based thermoplastic polymer is a biopolymer that is being widely explored as a replacement for conventional polymers. Since thermoplastic starch suffers from mechanical defects, certain mechanical and thermal properties of starch-based polymers can be improved by incorporating fillers or reinforcements derived mainly from natural substances. This article reports the preparation, physicochemical, and mechanical characterization and biodegradation of starch-based bioplastics extracted from potato (Solanum tuberosum) peels using glycerol (G) as plasticizer and reinforced with carob powder, a readily growing plant in Mediterranean climates. The present study investigates the effect of incorporating different proportions (0, 2, 5, 10, and 15 wt.%) of carob powder (Cb) in the films thus prepared. These biopolymer films were fully characterized using analytical techniques including Fourier transform infrared spectroscopy with attenuated total reflection (FTIR/ATR), thermogravimetric analysis (TGA/DTG), X-ray diffraction (XRD), optical microscopy (OM), Scanning electron microscopy (SEM), mechanical evaluations, and biodegradability assessments. The biodegradability of the obtained bioplastic samples was evaluated. Scanning electron microscopy (SEM) revealed strong interfacial adhesion between the constituent filler and the polymer matrix.