Contribution to the Study of the Water Behavior of Starch-Based Composite Films

In our previous studies, we developed a composite based on cassava starch. However, it is observed, like all starchy materials, that it is very hydrophilic and its behavior depends on its water content. This is explained by the attachment of water molecules to the hydroxyl groups of starch via hydrogen bonds. The barrier to water absorption has been reinforced by the incorporation of natural hydraulic lime of the NHL-3.5 type. This study aims to contribute to the knowledge of the water behavior of starch-based composite films. Here, it is the study of the diffusion and absorption of water vapor in a biofilm made of cassava starch reinforced with coconut fibers. To do this, we carried out tests on the sample which made it possible to obtain measurements concerning the hydric behavior of the material. Two approaches were used to evaluate these phenomena under well-defined conditions. The two methods contribute to the same result for the hydric behavior of the composite. The value of the diffusion coefficient obtained is 0.723.10-3 mm2/d. The results obtained are convergent and consistent with those obtained in the literature.