A new and comprehensive approach has been developed for the identification of carboxylic acids in virgin crude oil. Knowledge of the structures of these acids is relevant to questions concerning the origin of petroleum and the origin of life. The identification involves initial conversion of acids, via the corresponding alcohols and their p-toluene sulfonate esters, to hydrocarbons. The hydrocarbons are separated by a combination of silica gel and gel permeation chromatography and identified by ultraviolet, infrared, and high resolution mass spectrometry. For the acidhydrocarbon conversion, proof was obtained for the maintenance, on an average statistical basis, of most of the carbon skeletal structures of the original acids. The structure determination of the hydrocarbons and the retention of carbon skeleton during conversion permits identification of many classes of carboxylic acids not previously discovered in virgin crude oil. These classes include polycyclic naphthenic, mono-, di-, and polynuclear aromatic, mono-and dibenzthiophenic, carbazolic, and phenolic types. This identification procedure affords the first semiquantitative assessment of carboxylic acid classes in a crude oil relative to all of the acids present.
The weight-average molecular weights of a series of fractions from two structurally different types of perfluoropolyether fluids were determined by low-angle laser light scattering. The limiting viscosity numbers of both sets of fractions were measured in Freon W and related to molecular weights. By using established polymer solution theory, the coil dimensions of the molecules were calculated. Samples from both sets of fractions were subjected to analysis by gel permeation chromatography and the coil dimensions were derived by using the principle of universal calibration. Results from both methods agree well. Bulk viscosities and molecular weights were correlated.
A series of polyisobutene and polystyrene fractions was subjected to gel‐permeation chromatography at 150°C. The two types resulted in distinctly different calibration curves in a plot of projected, extended chain length versus elution volume. The average end‐to‐end distances of the samples were determined by intrinsic viscosity measurements. It was found that these data plotted versus elution volume could be represented by a common curve for both polymer types. The elution volumes of the polyisobutene series were determined at three additional temperatures, 35, 70, and 110°C. It could be shown that elution volume is again determined by polymer coil size at the temperature of measurement.
SynopsisThe viscositiei of two structurally different peduoropolyether fluids were determined at a series of temperatures and pressures, from 25 to 100°C and from 1 to loo0 bars. Flow activation energies and volumes as well their temperature and pressure coe5cients were derived. An attempt was made to relate measured and derived quantities to the compound structures.Both materials are random copolymers. For fluids of the Fomblin Y structure, NMR measurements indicate that m > > n, while for the 2 type, rn makes up approximately 40% of the material and n SOW. The subsequent experiments
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