Processing and characterization of LDPE/starch/PCL blends

Low-density polyethylene/plasticized starch/polycaprolactone blends were processed by conventional extrusion, injection molding, and film blowing techniques. The glass transition temperatures of plasticized starch were determined using differential scanning calorimetry. The blends were characterized by mechanical property measurements and scanning electron microscopy. The blend properties were found to depend not only on composition but also on the generated morphology. In films the fine dispersion of polycaprolactone phase in the polyethylene/starch matrix resulted in mechanical property increase, while in injection specimens there was property decrease due to phase coalescence. It appears that the different conditions existing at the two different shaping processes i.e. film blowing and injection molding could account for the final obtained morphology.