The rheological measurements were carried out with an MCR-702e rotational rheometer (Anton Paar, Austria) equipped with a 25 mm diameter parallel-plate. To evaluate the steady flow behavior of the materials, steady-state shear tests were performed at 180°C within a shear rate range of 0.05-100s -1 , with a measuring gap of 0.5 mm. Later, the flow parameters were determined by fitting the experimentally obtained viscosity data at low shear rates ( γ < 10s -1 ) to the power-law fluid model (Eq. 3) .