Effect of Plasticizer Concentration on the Physicochemical Properties of Starch-based Bioplastic Prepared from Potato Peels

Abstract

Environmental, economic, and waste management concerns are growing as a result of the proliferation of plastics in the environment. As a potential solution to the problem of plastic pollution, glycerol plasticized starch-based bioplastics were investigated for their biodegradability. There are numerous uses of starch, a biopolymer derived from organic waste, due to its unique characteristics, such as its flexibility, degradable nature, and low cost. In the present work, starch was extracted from Solanum tuberosum (potato) peels, and starch-based bioplastics with different concentrations, i.e., 2.4 %, 24.3 %, 36.5 %, 48.6 %, and 97.2 % of glycerol plasticizer were prepared by following the casting method. Starch and bioplastics were analyzed using Fourier Transform Infrared (FTIR) spectroscopy, and their physicochemical properties were evaluated. The FTIR spectra of bioplastics with varying glycerol concentrations showed peaks at 3278 cm-1, 1643 cm-1, and 995 cm-1 corresponding to –OH, -C=O, and –C-O, respectively, confirming the formation of bioplastics. The water absorption test revealed that the bioplastic with high glycerol concentration, i.e., 97.2%, had a more significant percentage of water absorption, i.e., 79 percentage, compared to 37 % for bioplastic with low, i.e., 2.4% glycerol concentration. Water molecules enter more easily into plasticizer-rich materials, due to which bioplastic containing high glycerol concentration decays faster, i.e., in 52 days. Furthermore, a higher percentage of glycerol allowed the bioplastics to absorb acid solution for up to 42 hours and basic solution for up to 45 hours without being dissolved.