Preparation of Spherical MgCl₂‐Supported Late‐Transition Metal Catalysts for Ethylene Polymerization

Abstract

Summary: Facile and effective immobilization of late‐transition metal catalysts, 2,3‐bis‐(2,6‐diisopropylphenyl)butane diimine nickel(ii) dibromide (A) and 2,6‐bis‐[1‐(2,4,6‐trimethylphenylimino)ethyl]pyridine iron(ii) dichloride (B), for ethylene polymerization has been achieved, using spherical MgCl2 supports obtained by thermal dealcoholization of MgCl2 · 2.56C2H5OH instead of using supports of type MgCl2/AlRn(OEt)3−n. BET, XRD, IR, SEM, GPC, and DSC analyses indicate that the composition and structure of the supports, the activities of the supported catalysts, and the properties of the resultant polymers are strongly dependent on the dealcoholization temperature. The support SP‐3 obtained by treating MgCl2 · 2.56C2H5OH at 170 °C for 4 h is very effective for immobilizing late‐transition metal FeII and NiII catalysts. Compared with the corresponding unsupported homogeneous catalysts, a significant increase in activity is observed for the SP‐3 supported catalysts in ethylene polymerization, and the kinetics of polymerization is stable during the reaction process. In addition, replication of the support morphology is found in final polymers.Kinetic profiles of ethylene polymerization using SPC‐4, SPC‐5, and SPC‐6 under 1.0 MPa and at 70 °C.imageKinetic profiles of ethylene polymerization using SPC‐4, SPC‐5, and SPC‐6 under 1.0 MPa and at 70 °C.

Preparation of Porous Anhydrous MgCl2 Particles by Spray Drying Process

“…The higher crystallographic disorder was reported to be suitable for transition metal catalysts [15]. The results indicate that all alcohols using in this research can decrease the crystal structure of -MgCl2.…”

Iron-Based and Cobalt-Based Olefin Polymerisation Catalysts

“…In addition to other polystyrene [138] and silica supports [139,140,141,142,143,144] , iron and cobalt precatalysts have been immobilised on calcosilicate [145] , magnesium dichloride [146,147,148,149] , MCM-41 zeolite [150,151] , clay [152] and fluorotetrasilicic mica [153] . Supported systems have also been examined using alternative activators [154,155,156,157,158,159] .…”

Copolymerization of Ethylene with Vinyl Monomers using Heterogeneous Catalysts Consisting of α‐Diimine Ni(II) Complexes Immobilized into a Fluorotetrasilicic Mica Interlayer in the Presence of an Alkylaluminum Compound

“…In addition to the basic study, many of the supported catalysts based on these α ‐diimine complexes were actively investigated due to their practical use. 5–23 As an ordinary method, the impregnation of the metal complexes onto MAO‐treated SiO 2 was attempted for the preparation of the supported catalysts. These catalysts well controlled the morphology of the polyethylene particles and showed a high activity for the polymerization of ethylene 5.…”