Variation of flow induced phase morphology of fluoroelastomer and polycarbonate blends and their mechanical properties.

The variations of the flow induced phase morphology of fluoroelastomer/polycarbonate (FL/PC) extruded blends and their mechanical properties were investigated in this paper. The phase morphology and mechanical property of extruded blends under the capillary die were examined by scanning electron microscope (SEM) and tensile machine, respectively. From SEM observation, the dispersed phases in the longitudinal direction for these extruded blends were categorized as sphere, ellipsoid, rod, and fiber. Furthermore, the processing window for the deformation of phase morphology in the longitudinal direction for FL/PC 10/90 w/w and 25/75 w/w extruded blends at 235 and 260 °C was studied. As shear stress was smaller than 7.0 × 10⁴ Pa, the spherical phase almost did not deform. The transformation from the sphere to the fiber form occurred in the range of shear stress 7.0 × 10⁴ Pa and 15.8 × 104 Pa. In particular, as shear stress was larger than 15.8 × 10⁴ Pa, the fiber broke up into a series of small droplets. Finally, it was concluded that the morphology with the mixture of fiber-like and spherical structures in the longitudinal direction could enhance the FL/PC blends with longer break elongation and higher Young’s modulus. [ABSTRACT FROM AUTHOR]