Theoretical Calculation of the Pressure Dependence of Liquid Hydrocarbon Viscosities

The extension of the significant structure theory of viscosity to the calculation of the viscosities of some selected liquid hydrocarbons such as $\mathrm{n‐}{\mathrm{C}}_{12}\mathrm{,\; n‐}{\mathrm{C}}_{15}$ , and $\mathrm{n‐}{\mathrm{C}}_{18}$ , etc., has been made. In this derivation, the explicit functional expressions of the molar solidlike volume $V_s$ and the intermolecular potential $\mathrm{\phi (a)}$ were introduced. The agreement between theory and experiment over a wide temperature (35–135°C) and pressure range (1–3600 bars) is quite satisfactory. The advantage of this treatment is that thermodynamic as well as transport properties are calculated from this same model of the liquid state.