ABSTRACT
Naturally occurring cycloaliphatic materials have been generally recognized as important constituents of petroleum for a century [1-3]. “Naphthenes” [4] contain at least one ring while “paraffins” contain none. The different properties, both good and bad, of comparable products derived from naphthenic crude oil and paraffinic crude oil have been ascribed to the relative proportion of cyclic and acyclic molecules. Aromatic compounds also occur naturally in crude oils, and, in general, mineral oil base stocks contain all three classes of compounds in varying proportions.
