Products from the oligomerisation and polymerisation of ethylene are ubiquitous in daily life. These products represent a major revenue stream for the commodity chemicals industry which, along with academia, has driven research and development into the control of polymer properties via manipulation at the molecular level.
This research, conducted at Imperial College London and funded by INEOS, focuses on the synthesis, characterisation, and properties of non-Cp transition metal complexes, featuring terphenyl and aromatic ligands, and their application in the oligomerisation and polymerisation of ethylene. Conditions for the most promising candidates in catalysis have been investigated and optimised for lab conditions. The effects exhibited by these systems on polymer microstructure in terms of molecular weight, molecular weight distribution, dispersity and degree of branching have also been demonstrated. In addition, a new analytical framework is presented for describing product distributions arising from the oligomerisation and polymerisation of ethylene. This framework elucidates the mechanisms of the systems under consideration, and expounds general mathematical considerations for characterising ethylene oligomer and polymer product distributions.
Chapter 1 presents the aims and objectives of this thesis and introduces several key concepts relevant to ethylene polymerisation.
Chapter 2 focuses on the synthesis and characterisation of novel non-Cp Group 4 η1- complexes, featuring terphenyl ligands, and their performance as ethylene polymerisation catalysts.
Chapter 3 presents the synthesis and characterisation of non-Cp Group 4 η6- and η4- complexes, featuring aromatic ligands, along with a theoretical consideration of their structure.
Chapter 4 includes homogeneous and supported ethylene polymerisation results using the non-Cp Group 4 η6- and η4- complexes from Chapter 3.
Chapter 5 describes a detailed analytical framework for considering product distributions from transition metal catalysed ethylene oligomerisation and polymerisation processes.
Chapter 6 gives experimental procedures and supplementary information relevant to Chapters 2 – 5.