Synthetic lubricants: star-branched oligomers via metathesis/dimerization of 1-octene and or 1-decene

Structure and Properties of Poly-α-olefins Containing Quaternary Carbon Centers

“…The improvements in the viscosity− temperature behavior and the low-temperature fluidity are related to the microstructure of the polymerization product. 1,[7][8][9]13 As the content of 1-olefin dimer in the reaction mixture decreases, the kinematic viscosity at 100 °C and the pour point of the product obtained with catalytic TiCl 4 / Et 2 AlCl increase (Table 4, runs 1−6). The steric hindrance causes 1-decene to polymerize to a higher degree than that seen with the 1-decene dimer, and it leads to an increase in the degree of polymerization and the molecular weight of the product, causing the kinematic viscosity to increase and the low-temperature fluidity to decrease.…”

“…This is because products containing quaternary carbons have more carbon atoms distributed on the branch chains, the product is structurally more compact, and the product has a higher degree of linearity with a linear polymer backbone and other branches. The polymers with quaternary carbon centers have a smaller rotation radius than polymers without such centers 9 and have weaker interactions with adjacent molecular segments and a smaller sweep volume, which gives products with quaternary carbon centers excellent low-temperature flow performance. Besides, further research shows that products containing quaternary carbons have better oxidation stability compared to that of the commercial PAO base oil because of the saturation of quaternary carbons (Table S1, Supporting Information).…”

“…When the kinematic viscosities of the products at 100 °C are similar, the viscosity index of the polymerization product obtained using the 1-olefin dimer as the reactant (Table , run 3) is higher than that of the 1-decene oligomerization product (Table , run 5), and the pour point of the product obtained in run 3 is lower than that of the oligomerization product. The improvements in the viscosity–temperature behavior and the low-temperature fluidity are related to the microstructure of the polymerization product. ,− , As the content of 1-olefin dimer in the reaction mixture decreases, the kinematic viscosity at 100 °C and the pour point of the product obtained with catalytic TiCl 4 /Et 2 AlCl increase (Table , runs 1–6). The steric hindrance causes 1-decene to polymerize to a higher degree than that seen with the 1-decene dimer, and it leads to an increase in the degree of polymerization and the molecular weight of the product, causing the kinematic viscosity to increase and the low-temperature fluidity to decrease.…”

“…The obtained polymerization product had excellent performance, and approximately 80% of the components in the product were C40 hydrocarbons. Nifant’ev et al validated the results reported by Yury, and the oligomerization products from the oligomer have a “star-branched configuration”, meaning that the hydrocarbons have one or two alkyl groups of 6–10 carbons each attached near the center of normal paraffin, such as a trimer of 1-decene, and star-branched oligomers containing a quaternary carbon center have been shown to have the best lubricating properties. ,− Nelson and Heckelsberg used a two-step method to obtain the product of this star-branched oligomer. In the first step, a mixture of 1-octene and 1-decene monomers was reacted using a ruthenium catalyst to produce C14 and C16 species as well as a C18 species with an internal olefin.…”

Catalytic Metathesis of Alkenes

“…Phillips developed a two-step process in which l-octene and! or I-decane is first metathesized to a mixture ofC 14 -C 1S internal alkenes which is then dimerized to lube oil range hydrocarbons [125].…”