4. Conclusions
Films’ water vapor permeability have strong dependency on
solubility and water diffusion coefficients and, consequently, on
relative humidity gradient range, presenting values up to 2–3 times
greater at 33–64% than at 64–90%, depending on film formulation.
Therefore, it is important to determine this property based on the
environmental conditions the film will be used.
The incorporation of cellulose fibers reinforces mechanically
starch films, which have higher tensile strength and lower deformation
capacity. The reinforced films present lower water vapor
permeabilities if compared with starch films without fibers. As
cellulose fibers are biodegradable and available at low cost, their
use as reinforcing agent is a viable alternative to improve the
properties of starch-based films.