Viscosity measurementsViscosity wer

Viscosity measurements
Viscosity were measured by rotational viscometer (Rheotest
2-Germany). The investigated samples were introduced into the
“S2” cylinder of the viscometer. The developed shear stresses at
different shear rates ranging from 1.00 to 437.4 S1 as described by
Abd-Elrashid, Samah, and Hanan (2004); from which the slope of
the relation between shear stress and shear rate represented the
overall apparent viscosity. The apparent viscosity was calculated
according to the following formula:
Apparent viscosity h ¼ s=g  100 (2