摘要 |
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 C6-C20 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.
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