The investigation of novel non‐metallocene catalysts with phenoxy‐imine ligands for ethylene (co‐)polymerization

Abstract

Phthaldialdehyde and phthaldiketone were treated with substituted phenols of 2‐amino‐4‐methylphenol, 2‐amino‐5‐methylphenol and 2‐amino‐4‐t‐butylphenol, respectively, and then treated with transition metal halides of TiCl4, ZrCl4 and YCl3. A series of novel non‐metallocene catalysts (1–12) with phenoxy‐imine ligands was obtained. The structures and properties of the catalysts were characterized by 1H NMR and elemental analysis. The catalysts (1–12) were used to promote ethylene (co‐)polymerization after activation by methylaluminoxane. The effects of the structures and center atoms (Ti, Zr and Y) of these catalysts, polymerization temperature, Al/M (M = Ti, Zr and Y) molar ratio, concentration of the catalysts and solvents on the polymerization performance were investigated. The results showed that the catalysts were favorable for ethylene homopolymerization and copolymerization of ethylene with 1‐hexene. Catalyst 10 is most favorable for catalyzing ethylene homopolymerization and copolymerization of ethylene with 1‐hexene, with catalytic activity up to 2.93 × 106 gPE (mol Y)−1 h−1 for polyethylene (PE) and 2.96 × 106 gPE (mol Y)−1 h−1 for copolymerization of ethylene with 1‐hexene under the following conditions: polymerization temperature 50 °C, Al/Y molar ratio 300, concentration of catalyst 1.0 × 10−4 L−1 and toluene as solvent. The structures and properties of the polymers obtained were characterized by Fourier transform infrared spectroscopy, 13C NMR, wide‐angle X‐ray diffraction, gel permeation chromatography and DSC. The results indicated that the obtained PE catalyzed by 4 had the highest melting point of 134.8 °C and the highest weight‐average molecular weight of 7.48 × 105 g mol−1. The copolymer catalyzed by 4 had the highest incorporation of 1‐hexene, up to 5.26 mol%, into the copolymer chain. © 2012 Society of Chemical Industry

Prominent Spatial Structure and Synergistic Linkage Effects in Bimetallic Titanium Olefin Polymerization Catalysts

“…Combining the above comprehensively, based on our previous experience, − we recently discovered a novel phenol-oxygen bridged binuclear metallocene complex prepared with [Me 2 Si­(C 5 H 4 ) 2 ]­TiCl 2 and hydroquinone, which can effectively catalyze the copolymerization of ethylene-1-octene. The introduction of phenoxy groups can shield the axial sites more effectively and thus delay chain transfer and β-H elimination, increasing the polymer molecular weight.…”

Vinyl-type homo- and copolymerization of norbornene catalyzed by bis(phenoxyimine) titanium complex

“…Early transition metal catalysts occupy an important position in NBE polymerization, especially titanium and zirconium complexes. In recent years, single‐site catalysts have been applied in olefin polymerization, due to their abilities to lead to homogeneous systems and well‐defined products compared to multisite Ziegler–Natter catalysts .…”

Highly Active Copolymerization of Ethylene and N-Acetyl-O-(ω-Alkenyl)-l-Tyrosine Ethyl Esters Catalyzed by Titanium Complex

“…Copolymerizations of ethylene with N -vinyl-2-pyrrolidinone and N -isopropylacrylamide were performed by [P, O] palladium complexes [ 13 ]. In our group’s previous work, copolymers of ethylene and α-olefins or polar monomer were prepared via non-metallocene catalysts with [N, N, O] [ 14 ], [N, N, N] [ 15 ], and [N, N, O, O] [ 16 , 17 ] ligands. In these investigations, the comonomers used were vinyl organics; biomass based monomers were not involved.…”