Morphology evolution of a liquid crystalline polymer in polycarbonate matrix enhanced by the addition of glass beads

Polycarbonate (PC)/liquid crystalline polymer (LCP)/glass bead (GB) composites filled with various volume fractions of GB were melt blended and characterized with theological measurements and morphological observation. The study showed that the morphology evolution of LCP droplets from spheres and ellipsoids to long fibrils during the flow was enhanced by the addition of GB. Increasing shear rate also promoted the fibrillation of LCP. At the first glimpse, increasing the apparent shear rate significantly decreased the viscosity ratio (p) and increased the capillary number (Ca), which facilitated the deformation and fibrillation of LCP, while adding GB affected these parameters less. But a 5% incorporation of GB produced a more pronounced fibrillation effect than an 8-time increase of the apparent shear rate. Image analysis and model establishment were conducted to demonstrate that a high local shear, existing between the closely nearby rotating spheres, increased Ca effectively and promoted the LCP fibrillation even at lower apparent shear rates. (c) 2005 Elsevier Ltd. All rights reserved.