Preparation and characterization of poly(vinyl alcohol)/gum tragacanth/cellulose nanocomposite film

The effects of gum tragacanth obtained from two species of Astragalus Gossypinus (GT‐G) and A. Parrowianus (GT‐P) at two levels of 10% and 30% combined with cellulose nanofibers (CNF; 5%) on the physico‐mechanical and structural properties of polyvinyl alcohol (PVA) nanocomposite film were investigated in this study.

The water solubility and water vapor permeability of the films decreased with increasing the content of both gums, especially in the film containing 30% GT‐P. The highest values of the tensile strength (39.3 MPa) and elongation at break (445%) belonged to the treatment containing 10% GT‐P (90/10P/0).

The FTIR and DSC analyses confirmed good interactions between GT and PVA in the 90/10P/0 treatment. SEM images indicated the dense structure of this film as the optimum treatment. Although the presence of CNF in the films containing GT‐G improved some properties, especially the Young modulus, it impaired all the functional properties of nanocomposite GT‐P film.