Sunflower Oil Industry By-product as Natural Filler of Biocomposite Foams for Packaging Applications

Abstract

The use of agroindustry by-products as reinforcements and/or composites filler is an innovative and economically attractive option that is still under study. Hence, the present work aims to study composite foams based on cassava-starch and sunflower oil press cake (SOPC), an oil industry by-product, using urea as an additive to enhance the biocomposites foaming capacity. Filler content (0, 20, and 40 wt%) and urea addition effect on foam morphology, physical properties and mechanical behaviour were analysed and compared to a benchmark polystyrene (PS) foam. In comparison with conventional PS foams, biofoams containing urea presented comparable mechanical properties yet higher hydrophilicity. Besides, formulations containing SOPC resulted in denser and harder materials and higher water uptake capacity than starch-based foams. Results provide further insights into biobased biodegradable foams development using agroindustrial residues as raw material and urea as foaming agent, with promising characteristics for food packaging.