Effect of the storage conditions on mechanical properties and microstructure of biodegradable baked starch foams

Abstract

Starch-based foams (SBFs) were prepared with corn, potato, tapioca, and chayotextle starches. A compression baking process was used to develop the SBFs. Biodegradation studies showed that different sources of starch have a particular behavior. The starches showed values of degradation of ~85%, while the degradation of SBFs was ~70%. The SBFs were conditioned at relative humidities (RHs) of 0 and 75% and temperatures of 4 and 65°C. The starch source used to prepare the SBFs did not have an effect on the mechanical properties, but the storage conditions showed a significant effect on those properties; an increase of RH causes an increase in the mechanical properties. A similar behavior was observed in the conditioned SBFs at different temperatures. The increase of the storage temperature showed a slight reduction in the values of elongation at break. Microscopy revealed that the conditions of RH and storage temperature affect the internal structure of the SBFs.