Effect of corncob-derived cellulose on physicochemical and rheological properties of poly (vinyl alcohol)-based film

Abstract

Films and coatings enhance quality and shelf life for packaging applications. In this study, we investigate the effect of different celluloses on poly (vinyl alcohol)-based composite film. Toward this, cellulose is extracted from corncob (using the kraft pulp process), and also commercially available cellulose is used to synthesize the composite films. The films were characterized using field emission scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, UV spectroscopy, water vapor permeability, moisture content, swelling index, and rheological techniques. The results demonstrate that adding extracted cellulose and commercial cellulose to the PVA film-forming solution enhanced tensile strength and decreased its elongation at break upon drying. The optimized results show that there is an increment of 192.4 % in the tensile strength (up to 53.52 MPa) compared to the neat PVA film. The commercial cellulose exhibits better crystallinity than the extracted cellulose in the XRD test. Also, rheological experiments were carried out to understand the film-forming solutions’ viscoelasticity as a function of temperature. The sol–gel transition shows that the extracted cellulose exhibits higher shear modulus and low gelation temperature compared to the other.