PROCESSING-INDUCED EFFECTS ON RHEOLOGICAL BEHAVIOR OF BIODEGRADABLE STARCH/POLYCAPROLACTONE BLENDS

摘要

Extrusion effects on rheological properties of starch/polycaprolactone (PCL) composites were investigated. Different extrusion conditions that involved varying extrusion temperature, screw speed and screw geometry were adopted to process the composites. Melt viscosity along with extrudate swell of the extruded samples were measured via a rheometer and an extrudate-swell detector. The results indicate that either high extrusion temperature or shear is effective for reducing the melt viscosity, but enhancing the exrudate swell. However, it appears that there are no significant differences in melt viscosity as well as extrudate swell among starch/PCL samples processed by different screw speeds. The destruction of starch granules during the processing of starch/PCL composites may be the cause for the peculiar rheological behavior.