the disclosure reveals that aromatic structures can be introduced into the molecular structure of polyalpha - olefin lubricant oligomers by subjecting the polyalpha - olefin to a dehydrocyclization reaction which converts a portion of the pendant or branching alkyl groups in the recurring polymeric unit of pao to aromatic structures . when the starting material for dehydrocyclization is pao prepared by oligomerization of c 6 - c 20 alpha - olefins in contact with reduced chromium oxide catalyst on porous support the dehydrocyclization reaction produces a lubricant oligomer with increased aromaticity without significantly degrading the viscometric properties of the feedstock lubricant , particularly the high vi of the starting material . the aromatic structures introduced lend increased thermal stability , wear resistance and solubilizing characteristics to the liquid lubricant oligomers so modified . the polyalpha - olefins produced by the dehydrocyclization process comprise novel compositions of matter containing up to five weight percent of aromatic structure attached as pendant groups to the backbone of the polyalpha - olefin structure .