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.

农用副产品用作增强材料和/或复合材料填充剂是一种创新且在经济上有吸引力的选择，目前仍在研究中。因此，本工作旨在研究基于木薯淀粉和葵花籽油压滤饼（SOPC）的复合泡沫材料，这是石油工业的副产品，使用尿素作为添加剂来增强生物复合材料的发泡能力。分析了填料含量（0、20和40 wt％）和尿素添加对泡沫形态，物理性能和机械性能的影响，并将其与基准聚苯乙烯（PS）泡沫进行了比较。与传统的PS泡沫相比，含尿素的生物泡沫具有可比的机械性能，但亲水性更高。此外，与基于淀粉的泡沫相比，含有SOPC的配方可产生更致密，更坚硬的材料以及更高的吸水能力。