Effect of Silica Content on Cellular Structural and Hygroscopicity of Modified Cassava Starch Foam

Abstract The growth in polymer production is influenced by the high demand from the packaging sector. Expanded polystyrene (EPS) is one of these materials that is widely used in disposable packaging, however, this generates waste that occupies a large volume and is difficult to degrade. Starch, a naturally occurring and biodegradable polysaccharide, may be an alternative in the search for a renewable source material. However, starch foams have some limitations related to their hygroscopicity. The objective of this study is to analyze the influence of silica content (1%, 2%, and 3%) on the cell structure and surface hygroscopicity of cassava starch foams. The foams containing starch, glycerol, and water are produced by thermo‐compression molding. Results show that, at lower contents, silica acts predominantly as a nucleating agent, generating smaller cells in the foam. At the higher silica content, it plays a more efficient role in reducing the affinity of the starch for water. The formulation with 2% silica shows the highest density (0.232 g cm −3 ), impact strength (2067 J m −2 ), and contact angle (84.8°).