Preparation of biodegradable plastic from low density polyethylene and tapioca starch

Abstract

LDPE/tapioca starch blends at various composition were prepared and their properties, tensile strength and elongation at break, were investigated. In order to improve the mechanical properties of the blends, several compatibilizers i.e. glycerol monostearate, zinc stearate and epolene, were added at 1% by weight of total blend. The measurement of mechanical properties of each blend had been compared with corresponding LDPE/tapioca starch blend without the compatibilizer. The results had shown that the presence of glycerol monostearate or zinc stearate in the blends enhanced the mechanical strength much more than epolene and the one without compatibilizer. Particularly, the addition of epolene even decreased both tensile strength and elongation at break of the blends. In comparison with LDPE/corn starch blends, LDPE/tapioca starch blends at every composition had higher tensile strength and elongation at break in the presence of either glycerol monostearate or zinc stearate than LDPE/corn starch blends. By using scanning electron microscopic technic, it indicated that starch granules dispersed evenly in polyethylene matrix.