Desenvolvimento de bandejas biodegradáveis reforçadas com diferentes resíduos agroindustriais

Abstract

Pollution from unmanaged disposal of plastic waste in water and on land may result in microplastic formation, which can be from EPS-expanded packaging. To fight against this problem, we aimed to elaborate biodegradable starch expanded trays reinforced by different agro-industrial residues to improve the packaging properties. The residues Corncob, cassava hull, soybean straw, Araucaria seeds hull, yerba mate thin stalks, and leaves petiole stems residues were used as fillers. The trays added by 10% of each different residue and formed by thermal expansion of cassava starch. Moisture content, water activity (aw), density, sorption isotherms, microstructure and mechanical properties of the trays were evaluated. All residues had particle sizes around 250 µm. The lignin content ranged from 19.28% to 42.68%, the hemicellulose content from 4.8% to 12.75% and the cellulose content from 20.92% to 55.25% among the residues. The trays moisture ranged from 5.77% to 10.48%. The aw ranged from 0.5 to 0.6 demonstrating microbiological stability. The standard tray had the lowest density (158 kg/m3), and the highest were from Araucaria seeds hull and cassava hull (222 kg/m3). Xbs values ranged from 0.34 to 0.50, K ranged from 0.928 to 0.965, with R2> 0.95. The standard tray had the highest tensile strength, modulus of elasticity and lowest bending stress (0.763 MPa, 54.53 MPa and 0.02 MPa, respectively). The reinforced tray with yerba mate was the one that elongated the most (0.017 mm), and the one that most resisted to bending was the cassava hull tray (1.80 Mpa).