Date of Award

2-3-1989

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Chemistry

Abstract

The use of an ether analysis procedure consisting of a reductive ether cleavage reaction of sodium in hexamethylphosphoric triamide (HMPA) and tetrahydrofuran (THF) with direct carbon-14 acetylation was investigated for the analysis of the ether content of coal derived asphaltenes and preasphaltenes. The acetate uptake of the cleavage products was higher than the original phenol content. However, major changes in the elemental composition of the cleavage product obscured the result of the acetate analysis. Tetrahydrofuran contamination was investigated by deuterium labeled THF experiments. No THF incorporation was indicated. The primary source of the change in elemental composition was therefore attributed to hexamethylphosphoric triamide contamination.The gel permeation chromatography (GPC) retention characteristics of low molecular weight oligomers of polystyrene, poly-(4-methylstyrene), poly-(4-vinylanisole), poly-(2-vinylnaphthalene) and poly-(9-vinylanthracene) for the use as standards for the molecular weight analysis of coal derived asphaltenes and preasphaltenes were investigated. Using narrow molecular weight fractions, both the log MW and the Benoit universal calibration plots were constructed for each polymer system. None of the calibration plots for the polymer systems were colinear with the calibration plots constructed for the coal derived asphaltenes and preasphaltenes. Therefore, none of the polymer systems could be used as standards in the molecular weight analysis of the coal derived materials. The polymer systems displayed non-universal behavior in their Benoit plots indicating that solute gel interactions had an effect in the retention of these oligomers. The greater amount of interaction was found in the case of the poly-(9-vinylanthracene) system. Examination of the relative retention of volumes of coal derived materials indicates that the amount of interaction between the solute and the gel increases as the condensation of the material increases.

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