Rheological behavior of castor oil mixed with different pyromellitic esters

Abstract

The paper presents the rheological behavior study of castor oil mixed with different pyromellitic esters. The pyromellitic tetraesters used were obtained through the esterification of pyromellitic anhydride with a special alcohol of a complex alkyl-aryl structure (2-phenoxy-ethanol) in conjunction with a linear aliphatic alcohol with variable length (n-butanol, n-decanol). The influence of pyromellitic esters? structure and concentration was determined, as well as that of temperature, on the rheological behavior, by setting the dependence between the shear stress ? and the shear rate ?. The analysis of dependence between ? and ? demonstrates that the studied solutions have Newtonian behavior. The evolution of samples' viscosity with temperature was characterized by Arrhenius type equations, being established the values of viscous flow activation energy, Ea. This constant can be correlated with the effect of reducing friction in the presence of additives. It was also realized a characterization of annulus fluids flow under the effect of rotational motion, calculating the values of Taylor-Reynolds number (TaRe).