ON THE RHEOLOGICAL BEHAVIOUR OF FILLED POLYMER MELTS†

The viscosity of polymer melts increases when adding fillers. Experiments were conducted with styrene—acrylonitrile copolymers filled with various amounts of glass beads and short glass fibres on a rotational and a capillary rheometer. Further from literature some representative equations have been compiled describing the influence of fillers on the viscosity. Applied to the experimental results it was found that the relative viscosity (R, i.e. the ratio of the viscosities of the filled and unfilled melts, shows a pronounced dependence on the shear rate ? but not on the shear stress t.