kinetic and microstructural studies of cp2zrcl2 and cp2hfcl2-catalyzed oligomerization of higher α-olefins in mpao oil base stocks production

Herein a quenched-flow kinetic technique was applied to calculate the rate constants of 1hexene and 1octene oligomerization catalyzed by the cp2zrcl2 and cp2hfcl2/mao catalyst systems, and subsequently a mechanism for the higher αolefin oligomerization reaction was proposed. the oligomerization results showed that zr-based catalyst in the oligomerization of 1-octene had the highest activity of 17 in comparison to hfbased one with an activity value of 15 g oligomer/(mmolcat.h)). according to the obtained results, increasing monomer length led to a shift in molecular weight and polydispersity index value (mw/mn) to lower values. furthermore, the microstructureviscosity relationship was followed by the calculation of branching ratio and shortchain branching percentage. the obtained results revealed that, the oligomers synthesized by the cp2hfcl2 catalyst had lower short chain branching ratio value and shortchain branching percentages. according to the kinetic results, the initiation rate constant (ki) of zrbased catalyst was higher than that of hfbased catalyst, and the order of calculated propagation rate constants was zr>hf for both the 1-hexene and 1-octene-based oligomerizations.