Synthesis and Characterization of Bioplastic Derived from Chlorella sp. Residue Biomass

Abstract

The accumulation of plastic waste is a significant global pollution issue in the age of globalization. Despite their irreplaceable properties and multiple applications, conventional fossil-based plastics cannot decompose naturally in the environment, resulting in exponential accumulation over time. To address this problem, biodegradable and biobased plastics have been introduced as alternatives to fossil-based plastics. This study aimed to characterize bioplastics formulated from Chlorella sp. microalgae biomass. Various formulations of biodegradable plastics were developed using microalgae Chlorella sp. and tapioca starch, with varying levels of plasticizer glycerol or sorbitol (25 wt%, 50 wt%, or 75 wt% based on the weight of starch) and the addition of chitosan as a filler. The physical, mechanical, and chemical properties of bioplastics were characterized. The study found that the chlorella bioplastics were ductile and had low elasticity, despite the addition of glycerol or sorbitol. However, the bioplastic exhibited an exceptional rate of biodegradability, with 100% weight loss when buried in loamy soil for 7 days. Furthermore, the Chlorella bioplastic with 75 wt% of glycerol, without the addition of chitosan, exhibited the highest solubility at 62.35%. The results indicated that increasing the amount of plasticizer tended to increase solubility, with glycerol having a more significant effect than sorbitol. Meanwhile, chitosan loading reduced bioplastic solubility.