International Polymer Processing, Vol.24, No.1, 59-66, 2009
Effects of Extrusion Variables on Organoclay Intercalation and Properties of Tapioca Starch-Poly(Lactic Acid) Nanocomposite Foams
Tapioca starch (TS) and poly(lactic acid) (PIA), in 90: 10 weight ratio, were blended with 3 % Cloisite 10A were and prepared by a twin screw extruder. Screw speed, screw configuration, die nozzle diameter and moisture content were varied to determine their effects on organoclay intercalation. Selected structural, thermal, physical and mechanical properties were characterized by X-ray diffraction, scanning electron microscopy, differential scanning calorimetry, and Instron universal testing machine. The first (X-ray) diffraction peak was observed to shift to a lower angle compared to that of pristine Cloisite 10A. The first diffraction peaks for the nanocomposites were narrow, indicating a strong intercalated behavior. These results were observed for all extrusion variables using mixing and compression screws, screw speeds of 100, 135 and 175 min(-1); moisture contents of 14, 17 and 20%, and the nozzle diameters of 3 and 4 mm. These extrusion variables had significant effects on the structural, thermal, physical and mechanical properties, and glass transition and melting temperatures of TS/PLA /Cloisite 10A nanocomposite foams due to the intercalation of organoclay.