Viscosities of twenty well-defined, representative mineral-oil fractions have been determined at temperatures from 25 to 90 deg C (77 to 194 deg F) and at pressures up to about 1000 atmospheres (15,000 psi) with the aid of a falling-needle viscometer. An analysis has been made of both the present measurements and reliable data from literature, which chiefly concern mineral oils and pure hydrocarbons, but also include some silicones, fatty oils, and alcohols. Many literature data cover ranges of viscosity, temperature, and pressure that are more extensive than those of the authors. Newly developed empirical formulas are presented for the isobaric viscosity-temperature relationship, the isothermal viscosity-pressure relationship, and the complete viscosity-temperature-pressure relationship. The formulas have been found to be satisfactorily applicable to all the aforementioned liquids in a wide range, that is, generally, from about 20 to 150 deg C (68 to 302 deg F) and up to pressures of at least 3000 atmospheres (44,000 psi). Diagrams derived from these formulas have proved particularly suitable for a systematic study of the correlation between, on the one hand, the temperature and pressure variation of viscosity of the liquids concerned and, on the other hand, their chemical constitution. This is exemplified by the results for the mineral oils investigated. In fact, it proved possible, presumably for the first time, to establish for mineral oils a really satisfactory quantitative correlation between their viscosity-temperature-pressure dependence and their chemical constitution; the latter has been characterized by the carbon distribution according to the “Waterman analysis” in the form of the so-called n-d-M method.

Saturated fatty acid methyl esters from acetate to arachidate, methyl oleate, linoleate, linolenate, and erueate have been prepared in high purity. Densities, refractive indices, dispersions, ultrasonic sound velocities, and dielectric constants have been measured in the liquid state at 20 and 40C. In this first communication, the densities of the saturated compounds have been correlated with the Smittenberg relation. The following relations were derived: d~ ~ = 0.85407 + 0.18494/ (n + 0.096) and d4~ ~ = 0,84225 + 0.12904/(n-0.408). Molar volumes have been computed and checked for additivity.

The ultrasonic sound velocity of the unsaturated fatty acid methyl esters from acetate to nonadecanoate, methyl oleate, linoleate, linolenate, and erucate have been measured at 20C and 40C in the liquid state. Data of the saturated compounds were correlated with the Smittenberg relation and a reasonable fit was noted. The molar sound velocity according to Rao was computed from the observed values and increments for the CH2 group and for the double bond are presented.

Kinematic viscosities at 20C, 40C and at 70C have been measured for methyl oleate, linoleate, linolenate, erucate, and for the saturated fatty acid methyl esters acetate through nonadecanoate. Using a recently developed dynamic viscositytemperature criterion, log (1.200 + log 7) = A --S log (1 + t/135), the viscosity-temperature behavior of the saturated compounds could be characterized by one single parameter. J Present addres.s: Chevron Research Co., Richmond, Galif. 433. 433

Densities and refractive indices of the nil^, Ha, Hfi and the