Synthesis of Synthetic Hydrocarbons Via Alpha Olefins.

Abstract : Alpha olefins have been used for some time as a starting point to produce oligomers in the C20 -C40(+) range. As lubricants, these materialsl exhibit unique properties in some respects, while in others, are demonstratively poorer than lubricants derived from mineral oils. Thermal and oxidative stability of commercially available decene oligomer is compared to oligomer prepared by anionic catalylsis. The latter oligomers show somewhat improved stabilities as well as more well-defined isomeric hydrocarbon species. Thermal stressing of oligomers at 350 C in and atmosphere of hydrogen and, alternatively, deuterium, suggest that thermal decompostion is a true bulk property. Normal alkanes were observed as decomposition procucts, while only small amounts of deuterium were found in the decompostion products, suggesting that radical recombination is a predominate mechanism. NMR analysis of oligomer prepared form 1 decene-2-13C with boron trifluoride catalyst suggests that oligomerization involves secondary carboniumn rions resulting from a rapid isomerization of the alpha olefin. Anionic addition (telomerization) of ethylene to mesitylene and meta xylene yilelds straight chanin alkyl, aromatic oils in which the chain length, structure and point of attachment to the aromatic ring can be controlled. These oils exhibited characteristics poor oxidation stability, however, hydrogenation of the aromatic ring in the m-xylene telomer produced a marked improvement in oxidation stability producing an oil equivalent to polydecene.