Effect of anhydrides on the mechanical, thermal and morphological properties of TPS/PE blends made by one-step extrusion

Thermoplastic starch/polyethylene blends containing maleic anhydride (MAH), succinic anhydride (SA) and phthalic anhydride (PA) were prepared by one-step extrusion, in a single-screw extruder, in the presence of dicumyl peroxide. The morphological, mechanical and thermal properties of the blends were characterized by scanning electron microscopy (SEM) and thermogravimetric analysis and also by measuring elongation at break (%) and tensile strength (MPa). Blends made with MAH had better properties than those with SA and PA. The SEM showed that they also had better interfacial adhesion. Because of the existence of carbon-carbon double bonds in MAH, it could graft to the polyethylene chains and act as a compatibilizer during the extrusion process. [PUBLICATION ABSTRACT]