Rheological behaviour of castor oil mixed with different pyromellitic esters

Abstract

The paper presents the rheological behaviour study of castor oil mixed with different pyromellitic esters. The pyromellitic tetra-esters used were obtained through the esterification of pyromellitic anhydride with a special alcohol with a complex alkyl-aryl structure (2-phenoxy-ethanol) in conjunction with linear aliphatic alcohols with variable length (n-butanol, n-decanol). The influences of the structure and concentration of the pyromellitic esters as well as that of temperature, on the rheological behaviour were determined from the dependence between the shear stress τ and the shear rateγ. An analysis of the dependence between τ and γ demonstrated that the studied solutions exhibited Newtonian behaviour. The evolution of the viscosity of the samples with temperature was characterized by Arrhenius type equations, the values of activation energy of viscous flow, Ea, were established. This constant can be correlated with the effect of friction reduction in the presence of additives. Characterization of the annulus of fluids flow under the effect of rotational motion was also realized by the calculation of the values of the Taylor- -Reynolds number (TaRe). © 2014 (CC) SCS.