In addition to regular viscosity measurements (as described in Section 1.4.) additional viscosity measurements were performed using a CP50 geometry and 0.101 mm gap at 25 °C. For these additional viscosity measurements, the shear rate was held constant for 10 minutes at 1, 5, 10, 50, 100, 500 and 1000 s -1 before moving to the next shear rate to look for instability within the sample.