Steady shear and elongational flow characteristics have been measured for polystyrene melts filled with C
aCO
3 particles. The particle contents are 20, 40, 60 wt% and the average size of particles is 3 μm. The normal stress difference N
1 at a fixed shear stress σ decreases as the particle content increases. There is a relationship between N
1 and σ, N
1 ∝ σ
2, which is independent of particle content. The shear compliance J
s at a fixed shear rate γ decreases with increasing particle content but is almost independent of γ for each content of particles. The extrudate swell ratio of polymer melt decreases with increasing particle content, suggesting a reduction of elasticity. Mixing of the solid particles also increases the elongational viscosity and the extent of viscosity increase depends on the particle content. At small strains, the transient elongational viscosity η
E+ of C
aCO
3-filled systems is independent of strain rate. After the strain exceeds a critical value, η
E+ increases with strain rate and strain. When the strain rates are low, η
E+ of the unfilled polymer has a tendency to approach to a steady value, while the filled samples still exhibit an increase of η
E+ with strain.
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