Studies of Olefin Dimerization, Oligomerization, and Polymerization Catalyzed by Cationic (alpha-Diimine)Ni(II) Complexes
Abstract
The polymerization of olefins by transition metal catalysts is an area of tremendous commercial significance and academic interest. Over the past twenty years, substantial improvements have been made in the design and industrial employment of these catalysts, especially with the development of early transition-metal metallocenes. The development of cationic (alpha-diimine)nickel(II) and palladium(II) complexes which catalyze the polymerization of both ethylene and alpha-olefins to high polymers represents a major advance in the field of olefin polymerization catalysis. Through simple variations of the alpha-diimine ligand structure and reaction conditions, the polymer molecular weights, molecular weight distributions, and microstructures can be easily controlled. The work in this dissertation focuses on olefin dimerization, oligomerization, and polymerization reactions catalyzed by (alpha-diimine)Ni(II) complexes, with the general goal of gaining an increased understanding of the mechanism of olefin polymerization by these nickel systems. Chapter Two is a study of the effects of monomer concentration, reaction temperature, aluminum cocatalyst, and electron-donating or -withdrawing diimine ligand substituents on the (alpha-diimine)Ni(II)-catalyzed oligomerization of ethylene and the dimerization of propylene. Chapters Three and Five are an account of detailed investigation of the effects of reaction conditions and diimine ligand structure on the properties of polyethylene and poly(alpha-olefin)s produced by (alpha-diimine)Ni(II) complexes. The effects of these variables on catalyst productivities, as well as polymer molecular weights and microstructures are presented.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 17, 1999
- Accession Number
- ADA370369
Entities
People
- Steven A. Svejda
Organizations
- University of North Carolina at Chapel Hill