Recent developments in catalyst systems for selective oligomerization and polymerization of higher α-olefins

Abstract

In this study, a comprehensive review of the recent developments in the use of various types of homogeneous and heterogeneous catalysts for the dimerization, oligomerization and polymerization of higher linear alpha olefins, such as 1-butene (1-C₄), 1-pentene (1-C₅), and 1-hexene (1-C₆), 1-octene (1-C₈), up to the larger homologue, such as 1-eicosene (1-C₂₀), is discussed. By briefly tracing the historical studies of metallocene, Ziegler–Natta, ionic and Brønsted acid-type catalysts, the systems that have led to the design of novel complexes in the last few years are summarized. The recently evolved non-metallocene and single-site catalysts for the selective oligomerization of higher alpha olefins have also been discussed. The application of various analytical techniques, such as ¹H NMR and the ¹³C NMR spectroscopy study of molecular properties by GPC, DSC, and viscosity measurements have been highlighted. The microstructure of polymers and the mechanistic aspects that involve various types of insertions, chain transfer, and termination steps for each category of catalyst that selectively form dimer/oligomer/polymer is briefly presented. The impetus for future catalyst development, which is directly linked to the commercial application of these reactive higher alpha olefins, is underlined.