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 degrees (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 (T-g), tensile strength and modulus of elasticity of nanocomposites films.