Melt flow behavior in capillary extrusion of nanosized calcium carbonate filled PLLA/PCL bio-composites

摘要

Nanosized calcium carbonate (nano-CaCO3) filled poly-l-lactide (PLLA)/polycaprolactone (PCL) bio-composites were prepared by using a twin-screw extruder. The melt flow behavior of the composites, including the entry pressure drop, melt shear flow curves and melt shear viscosity were measured through a capillary rheometer operated at a temperature range of 170-200 °C and shear rates varying from 50 to 103 s-1. The melt shear flow roughly followed the power law, while the effect of temperature on the melt shear viscosity might be estimated by using the Arrhenius equation. Moreover, the relationship between the PCL weight fraction and the melt shear viscosity for the PLLA/PCL/nano-CaCO3 composite was described by a quadratic equation.