Simultaneously reinforcing and toughening plasticized starch film via regenerated cellulose as reinforcing phase

Using regenerated cellulose (RC) as reinforcing phase, a series of glycerol plasticized corn starch (PCS) films were developed via a simple casting pathway. Wide angle X-ray diffraction (WAXD) showed that compared to cellulose crystallites (CC), the RC, dissolved in NaOH/urea aqueous solution and then regenerated by water, exhibited a significant decrease in intermolecular hydrogen bonding. Scanning electron microscopy (SEM) confirmed that compared to CC, a better dispersion of RC in PCS matrix was achieved, and higher tensile strength and elongation at break was obtained. More important, an unusual simultaneous film reinforcing and toughening phenomenon occurred after the addition of RC. Even the weight ratio of RC was up to 20 %, the elongation at break was still higher than that of pure PCS film. A schematic was presented to demonstrate the dispersion features of RC in glycerol plasticized starch film and illustrate this unique mechanical behavior.