Studies on blow ability of cassava starch-LDPE composite using glycerol and palm olein as plasticizer for green biofilm production

This study aims to produce cassava starch (CS) based low density polyethylene (LDPE) biofilms with the addition of glycerol and palm olein as processing aids. Prior to blown film extrusion the CS-LDPE composite was prepared via blown film extrusion process. The composites were formulated with the addition of polyethylene-grafted-maleic anhydride (PE-g-MA) as a compatibilizer. The flow ability analysis of the produced CS-LDPE biofilms was conducted using melt flow indexer. The biofilms with addition of fixed amounts of palm oil based olein displayed excellent film blowing ability compared to glycerol. In addition, incorporating of CS to the biofilms significantly lower the physical-mechanical properties of the final products. This is due to the poor interfacial adhesion between starch and synthetic polymer. The melt index of CS-LDPE biofilms noted a significant decreasing trend caused by the incorporation of starch and plasticizers in the blends for both, glycerol and palm oil based glycerin. Scanning electron micrograph (SEM) of this biofilm with starch composition up to 30 wt% showed good dispersion of starch granular in the polymer matrix. SEM also found the images of starch particles seem to be embedded in the LDPE matrix.