Effect of glycerol concentration on the mechanical and physical properties of a bioplastic from coffee (Coffea arabica) husk

Abstract

The study developed and characterized a biodegradable bioplastic from coffee husks, taking advantage of this agroindustrial waste as raw material for a sustainable alternative to conventional plastics. Through a pre-experimental design, bioplastics were formulated with different concentrations of glycerol, combined with cellulose extracted from the husk, cassava starch, acetic acid and distilled water. The bioplastic was made using the casting method and mechanical properties such as tensile strength and elongation were evaluated, as well as physical properties such as thickness and moisture content. Formulation T1 stood out with better performance, achieving a maximum resistance of 2.03 ± 0.3 kg and an average thickness of 0.33 ± 0.005 mm. Statistical analyzes confirmed significant differences between the formulations, indicating that the glycerol concentration directly affects the characteristics of the bioplastic. The results showed that the material is biodegradable, reinforces the circular economy and constitutes a viable solution to reduce the environmental impacts of petroleum-derived plastics