Effect of glycerol content on mechanical, microstructure and physical properties of thermoplastic potato starch film

This study present the preparation of potato starch film with glycerol as a plasticizer through a solution casting technique. The effect of glycerol with varying concentrations (10%, 30%, 50% and 70%) on the tensile, microstructure and physical properties of potato starch film was investigated. Results shows that the increase of glycerol content caused the decrease in tensile strength, with the highest value of 13MPa was recorded for starch film containing 10% glycerol, whereas the elongation at break increased as the glycerol content increased from 10%-30%. Nevertheless, the elongation at break for plasticized films significantly decreased at a higher glycerol content due to anti-plasticization effect. Besides, the microstructure of the starch films showed gradual smoother surface, homogenous and good distribution, as the glycerol content increased. The thickness and moisture content of the films increased with increasing glycerol content due to the hygroscopic behavior of the plasticizer. Overall result shows that the addition of glycerol in potato starch film significantly influenced the properties of the films.