Synthesis of Biodegradable Plastic from Wak Banana Peel Starch with Glycerol as Plasticizer

Abstract

Biodegradable plastic from banana peel is durable and transparent. It breaks down naturally in the environment and can substitute traditional petroleum plastic, which is a source of pollution due to its slow degradation. This research is intended to improve the physical properties of biodegradable film obtained by the casting solution method from an Aceh variety of wak banana peel starch with glycerol as a plasticizer. The authors relied on a factorial completely randomized design with two replications. The variables included the concentrations of wak banana peel starch (6, 8, and 10%) and glycerol (2, 5, and 8%). The data were subjected to the analysis of variance (ANOVA). The physical tests covered tensile strength, elongation, water absorption, and biodegradation. The functional groups of biodegradable films were analyzed using Fourier-transform infrared spectroscopy (FTIR). The morphological structure was studied by scanning electron microscopy (SEM). The biodegradation test lasted for two and four days. The sample with less banana peel starch (6–8%) degraded faster. Higher glycerol concentrations (5–15%) affected the weight of the samples. The plastic samples with 15% glycerol degraded faster than the samples with minimal glycerol amount. A greater concentration of wak banana peel starch significantly affected tensile strength and elongation while the effect on water content and water absorption capacity was insignificant. Glycerol concentration affected water content and tensile strength, but had no significant effect on water absorption capacity and elongation. The ratio between the concentrations of wak banana peel starch and glycerol had a significant effect on tensile strength and water absorption capacity. The best results belonged to the sample with 8% wak banana peel starch and 2% glycerol. The research provided new options for utilizing banana peels as biodegradable packaging and an alternative to traditional plastic. The commercialization and scalability of this ecologically friendly plastic require furth er research.