Mitigating chain‐transfer and enhancing the thermal stability of co‐based olefin polymerization catalysts through sterically demanding ligands
Abstract
Sterically demanding Fe‐ and Co‐based olefin polymerization catalysts 2‐Fe and 2‐Co bearing 2,6‐bis(biphenylmethyl)‐4‐methylaniline substituted bis(imino)pyridine ligands were synthesized and evaluated for ethylene polymerization. The late‐transition metal complexes were characterized by X‐ray diffraction, NMR spectroscopy, and HRMS, while their resultant polymers were characterized by size‐exclusion chromatography and 1H NMR spectroscopy. While catalyst 2‐Fe was inactive, catalyst 2‐Co was found to polymerize ethylene and avoid any detectable chain‐transfer to aluminum events that are known to plague other Fe‐ and Co‐based catalyst systems and to limit molecular weight. Furthermore, 2‐Co displays virtually perfect thermal stability up to 80 °C and shows greatly enhanced thermal stability at 90 °C as compared to previously reported analogues. These observations are attributed to the extreme steric demand imposed by the ligand which mitigates catalyst transfer, deactivation, and decomposition reactions. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 3990–3995
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Sep 17, 2017
- Source ID
- 10.1002/pola.28783
Entities
People
- Brian K Long
- Nolan E. Mitchell
- W. Curtis Anderson Jr.
Organizations
- Army Research Office
- University of Tennessee