Post‐oligomerization of α‐olefin oligomers: A route to single‐component and multicomponent synthetic lubricating oils

Abstract

This article describes a synthetic route to single‐component and multicomponent base stocks for synthetic lubricated oils. The synthesis was carried out in two stages. First, oligomers of α‐olefins (1‐hexene, 4‐methyl‐1‐pentene, and 1‐decene) were prepared via reactions catalyzed by metallocene catalysts. The distribution of the oligomers with respect to their oligomerization number could be controlled by the reaction temperature. The oligomer mixtures were then fractionated, and the lightest components, dimers and trimers, were separated. Finally, the latter materials, branched α‐olefins containing vinylidene double bonds, were further oligomerized with cationic catalysts. One such material prepared in the two‐stage process, the dimer of the 1‐decene dimer (C40 product), has a kinematic viscosity of 6.4 cs at 100°C and a viscosity index of 147. It represents the first example of a single‐component base stock for synthetic lubricating oils. The post‐oligomerization procedure was performed on unfractionated oligomer mixtures as well, leading to an improved distribution of the final materials with respect to the carbon atom number. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Fair Look at Coordination Oligomerization of Higher α-Olefins

“…The presence of bulky alkyl or aryl substituents in the cyclopentadienyl rings resulted in decreasing activities of metallocenes and an increased content of higher oligomers; increasing the number of alkyl substituents entailed the same effect. The early results in the study of the oligomerization of α-olefins in the presence of zirconocenes 1 and 8 at Al MAO /Zr~200 [47] were complemented substantially by Nifant'ev et al [91], who established that under these conditions, the products of side reactions (2-alkenes and alkanes) typically exceeded 10 wt %. Therefore, bis-cyclopentadienyl complexes at high Al MAO /Zr ratios have poor prospects for the oligomerization of α-olefins.…”

“…As compared with zirconocene 1, in the presence of the 6 dimer of sterically hindered olefin, 3-methylbut-1-ene was obtained with an average yield; substituted silanes and allylthiophenes also formed vinylidene dimers [41] (Scheme 2b). Note that the zirconium pre-catalysts 7 [44][45][46], 8 [47], 3 [48], 9 [49,50], and 10 [51] and the hafnium complex 11 [48], studied previously in α-olefin dimerization, were less active and selective in comparison with 6.…”

Double-bond isomerization of hexadecenes with solid acid catalysts

“…This supposition can be deduced from the greatly decreasing rates of oligomerization in batch oligomerization reactions [31]. The TOFs in batch reactors at longer times are more than two orders of magnitude less (10 −4 -10 −3 s −1 at temperatures below 170 • C) than the initial rates [31,47,48]. Therefore it is difficult to establish quantitative relationships between site density and oligomerization rate, although a qualitative connection undoubtedly exists, as shown in Fig.…”

Poly‐α‐olefin‐based synthetic lubricants: a short review on various synthetic routes

“…In 2009, Kissin et al reported oligomerisation of 1-hexene and separately 1-decene using nBuCp 2 ZrCl 2 and MAO with Al/Zr molar ratio of 200. 38 They have demonstrated that by changing the temperature from 70 C to 90 C, the percentage of dimer increased from 60% to 71%. The dimers obtained from two cases were further polymerised using AlCl 3 -supported, EtAlCl 2 -supported and silica-supported EtAlCl 2 , and the products were analysed using gas chromatography.…”

“…In 2009, Kissin et al . reported oligomerisation of 1‐hexene and separately 1‐decene using nBuCp 2 ZrCl 2 and MAO with Al/Zr molar ratio of 200 . They have demonstrated that by changing the temperature from 70°C to 90°C, the percentage of dimer increased from 60% to 71%.…”