Characterization of Thermal Diffusion Fractions of Petrolenes from a Mid-Continent Asphalt.

Constitution of Asphaltic Bitumen. Characterization of Bitumens by a Combination of Pyrolysis, Hydrogenation, and Gas-Liquid Chromatography

“…In Table XIII the presumed origin of the cyclanes formed in pyrolysis experiments with various model compounds and bitumens is indicated. The relatively high proportion of "isolated" rings in the pyrolyzates of bitumens tallies with the findings of Gardner and coworkers (7), for example, who exhaustively analyzed maltene fractions of bitumens that had been obtained by means of thermal diffusion.…”

“…Ariet and Schwever (7) also pyrolyzed asphaltic materials. They found that differences in the pyrograms are very real, but stated, "the general similarity of the results for widely different bitumens and fractions separatedthere from raises the question as to the feasibility of this technique in studying bitumens at this time.…”

Investigation of the Nature of Free Radicals in Petroleum Asphaltenes and Related Substances by Electron Spin Resonance.

“…Although x-ray determination of fa has not been made as yet, infrared spectral measurements show diminished intensity of the bands attributed to aromatic carboncarbon stretching and the aromatic carbon-hydrogen stretching and bending frequencies. Accompanying this apparent decrease in aromaticity was a (10). 6 Thermal diffusion fractions numbers 3 through 10.…”

“…To investigate the significance of the observed relationships in terms of origin and structure of the samples, Ng and /" values were derived for additional petroleum fractions, coals, carbon blacks, and graphite from data in the literature. The petroleum fractions were thermal diffusion cuts, prepared by Gardner and coworkers (10) from the pentane-soluble fraction of an 85 to 100 penetration asphalt, derived from a blend of Illinois and Oklahoma crudes by oxidation of a 200 penetration vacuum distillation residuum. Elementary analyses, Table III, show a somewhat higher carbon, a much higher hydrogen, and a lower content of the hetero elementsi.e., oxygen, nitrogen, and sulfur than those for the petroleum asphaltenes previously studied in this laboratory (8), Table IV.…”

Application of Spectroscopic Techniques to the Structural Analysis of Petroleum

“…As a result, structural parameters were estimated for the aromatic systems (Gardner et al, 1959). In addition, it was also demonstrated that the information derived by use of proton magnetic resonance was similar to that obtained using other spectroscopic methods (Ramsey et al, 1967).…”