DENSITY AND VISCOSITY OF LOW-MOLECULAR-WEIGHT TRIGLYCERIDES AND THEIR MIXTURES

The viscosities of tributyrin (C4:0) and binary mixtures of this triglyceride with a diesel fuel, tricaproin (C6:0), and tricaprylin (C8:0) were determined for the temperature range -5 to 85 degrees C and for shear rates of 1.62-64.7 s(-1). The resulting dynamic viscosities were fit to a power law model to obtain values for the consistency coefficient and the flow behavior index. These results indicated slightly pseudoplastic flow behavior (indices ranged from 0.94 to 0.99) for tributyrin and its mixtures. The calculated consistency coefficients for tributyrin and those previously obtained far tricaproin, tricaprylin and tricaprin were fit by a least-squares method to the three parameter Vogel model to account for the effect of temperature. An ideal solution relationship and the Kendall-Monroe model were used to predict the density and consistency coefficients, respectively, for binary and quaternary mixtures of these low-molecular weight triglycerides.