PROPERTIES OF EXTRUDED STARCH-BASED PLASTIC FOAM

Plastic foam was made with 25% amylose corn starch and polystyrene or polymethylmethacrylate. The foam was formed with a commercial extruder at 120 degrees C barrel temperature, 140 rpm screw speed and 6% moist ure content. X-ray diffraction analysis indicated grafting between sta rch and plastics. Shipping bulk density, water solubility index, sprin g index and compressibility of extruded loose-fills were determined an d compared with commercially available polystyrene and starch loose-fi lls. Loose-fills also were compared with various tests used by the loo se-fill packaging industry such as flowability, electrostatic adhesion , loaded bulk density, compressive creep and compressive set. Except f or the densities, the properties of the starch-based loose-fills compa red favorably with the commercial products.