Composition and Temperature Dependence of Shear Viscosity of Hydrocarbon Mixtures

Shear viscosities and densities have been measured from 50 C to as low as -56 C for five C10 hydrocarbons: n-decane, n-butyl cyclohexane, cis- decalin, n-butyl benzine and 2,7-dimethyl octane and their mixtures. A literature review of theories of hydrocarbon mixture viscosities has been carried out. It is shown that previous theories, in general, cannot give a good account of the mixture viscosities over the wide temperature range covered in this study. Two simple semi-empirical equations have been developed and applied to the description of the combined composition-temperature dependence of the viscosity of both the hydrocarbons studied under the present contract and two polycyclic hydrocarbons studied under a parallel Air Force Contract. The equations assume additivity of component free volumes in the mixtures and contain no more adjustable parameters than are required to account for the viscosities of the pure hydrocarbon components.