Synthesis and characterization of corn starch based biodegradable plastic: microstructural, structural, and decomposition studies for potential applications

This study focuses on the synthesis and characterization of biodegradable plastics using corn flour, vinegar, glycerin, and varying amounts of water. The biodegradable plastics were synthesized via a two-step process involving solvent casting and controlled physical foaming. X-ray diffraction patterns exhibited broad amorphous halos centered at 2θ ≈ 19.6°, alongside weak peaks at 15.1 and 23.3°, indicating a semi-crystalline nature. Scanning electron microscopy displayed a heterogeneous grain surface of starch granules with an average pore size of ~ 119−585 μm². The prepared biodegradable plastics have the highest porosity (~ 31.67%), depicting a loosely packed amorphous nature. Energy dispersion spectroscopy provided the elemental analysis of starch-based biopolymers. Fourier-transform infrared spectra showcased functional groups viz., hydroxyl (O-H) at ~ 3340−3365 cm^-1, carbonyl (C=O) at ~ 1717−1735 cm^-1, and glycosidic linkages (α-1,4) at ~ 917−926 cm^-1. The bioplastic samples have considerable degradation (up to 84.298%) in red soil in a week. Thus, such starch-based bioplastics can be used as alternatives to conventional plastics.