Chemical Science International Journal

Sunflower oil is the non-volatile oil compressed from sunflower (Helianthus annuus) seeds. Sunflower oil contains predominantly linoleic (48–7%), oleic (14–40%), palmitic (4–9%) and stearitic (1–7%). In general, viscosity measures the resistance of a liquid to flow. From a molecular point of view, viscosity is an indirect measurement of the internal friction between the molecules that constitute the fluid and which oppose liquid movement. Therefore, viscosity must have significant correlations with structural parameters of the fluid molecules.

The sunflower oil were investigated using a Haake VT 550 Viscotester developing shear rates ranging between 3 and 120 s^-1 and measuring viscosities from 10⁴ to 10⁶mPa.s when the HV₁ viscosity sensor is used. In this article we presented rheological models to study the behavior of sunflower oil. The constants A, B, and C were determined by Origin 6.0 software by fitting exponential curves obtained from experimental data. The one proposed relationship gives correlation coefficients close to one. For three-dimensional representation of the shear rate by shear stress at different temperatures we used Origin 6.0 software. From the diagram it is observed that at low temperatures sunflower oil has the highest shear stress and therefore dynamic viscosity highest at high temperatures sunflower oil has the lowest shear stresses and therefore dynamic viscosity lowest.