Studies on the oxidative behavior of base oils and their chromatographic fractions

Citation
A. Adhvaryu et al., Studies on the oxidative behavior of base oils and their chromatographic fractions, FUEL, 78(11), 1999, pp. 1293-1302
Citations number
42
Categorie Soggetti
Chemistry,"Chemical Engineering
Journal title
FUEL
ISSN journal
00162361 → ACNP
Volume
78
Issue
11
Year of publication
1999
Pages
1293 - 1302
Database
ISI
SICI code
0016-2361(199909)78:11<1293:SOTOBO>2.0.ZU;2-H
Abstract
A modified TP 306 test procedure is used to study the high temperature liqu id phase oxidation of five base oils and their hydrocarbon type subfraction s. The base oils are selected so as to cover a wide range of physiochemical characteristics. Qualitative as well as quantitative analysis of the base oils and their fractions were done using chromatographic (column, HPLC) and spectroscopic (MS, NMR, FTIR) techniques to gain a better understanding of their compositional and structural details. Oxidized materials were also s tudied and structural changes identified as a result of thermal oxidation. Relative oxidative degradation of different base oils is discussed in terms of their NMR derived structural models. The results indicate that polyarom atic and naphthenoaromatic compounds undergo more oxidative degradation tha n saturated molecules. The oxygenated polar compounds and deposits formed a re mainly derived from aromatic structures, which decreases as weight perce nt of the total base fluid as oxidation progresses. Alkyl substituted aroma tic structures showed larger decrease in chain length than purely paraffin (n- and iso-) compounds during oxidation. Spectroscopic data also indicated that alkylation of aromatics is mainly through alkyl radicals generated fr om long chain alkyl aromatics. (C) 1999 Elsevier Science Ltd. All rights re served.