Catalysis Science & Technology
The reactivity of a phenoxy-imine-ether system (FI)TiCl3/MAO was studied toward selective ethylene trimerization. This system was shown to either trimerize or polymerize ethylene depending on the reaction temperature. Its selectivity switches from a significant production of the trimerization product, 1-hexene (85 wt%, 520–450 kg1-hexene gTi−1 h−1) between 30 and 40 °C, to a moderate polyethylene formation (70–80 wt%, 60–70 kgpolyethylene gTi−1 h−1) at a higher reaction temperature (T > 60 °C). Polymerization was investigated based on an original “polymer-to-catalyst” strategy aiming at identifying the active species responsible for this side reaction. Using DSC, SEC and high temperature 13C NMR analyses, polyethylenes were found to exhibit high molar masses (>105 g mol−1) and a low 1-hexene content (<1 mol%) at any temperature. Kinetic studies support that trimerization and polymerization species are generated from the catalyst precursor at 40 °C but a parallel process may occur at a higher temperature. The increase of dispersity to 4.6 at 80 °C suggests a change from single to multi-site catalysis. The poor comonomer incorporation ability of the active species is reminiscent of a molecular Ziegler–Natta or a bulky post-metallocene catalyst.
For details: Titanium-based phenoxy-imine catalyst for selective ethylene trimerization: effect of temperature on the activity, selectivity and properties of polymeric side products
Astrid Cordier a, Pierre-Alain Breuil b, Typhène Michel b ,Lionel Magna b, Hélène Olivier-Bourbigou b, Jean Raynaud a, Christophe Boisson a and Vincent Monteil a
a UMR 5265, Laboratoire de Chimie Catalyse Polymères et Procédés (C2P2), Univ. Lyon, Université Claude Bernard Lyon 1, CPE Lyon, CNRS, Bat 308F, 43 Bd du 11 novembre 1918, 69616 Villeurbanne, France
b IFP Energies nouvelles, Rond-point de l'échangeur de Solaize, 69360 Solaize, France
For more information about Chemspeed solutions:
ISYNTH POSYCAT POSY
AUTOPLANT POSY
Catalysis Science & Technology
https://doi.org/10.1039/C9CY02056J
Copyright © Catalysis Science & Technology
For details please contact [email protected]
