Preparation and characterization of nanocomposite films containing starch and cellulose nanofibers

Starch nanocomposites films were successfully prepared using the isolated cellulose nanofibers (CNFs) at loading from 5 to 20% by solution casting. The morphology, crystallinity, surface hydrophobicity, water vapor permeability, opacity, and mechanical test of nanocomposites films were studied. The CNFs were uniformly distributed within these films up to 15% of CNFs. The incorporation of 20% CNFs in the composite film produced selective aggregation and, thus, inhomogeneity of the CNFs. The contact angle values increased from 49.46° (starch-only films) to 88.57° (CNFs loading at 20%). The incorporation of CNFs hinders the diffusion or permeability of water vapor through the composite. Addition of CNFs to starch films resulted in significant improvement in glass transition temperature (Tg), tensile strength and modulus of elasticity of nanocomposites films.