Experimental data on ethylene homo- and copolymerization with higher a-olefins (hex-1-ene, oct-1-ene, and dec-1-ene) by the catalytic system TiCl 2 {η 2 -1-[C(H)=N(2,3,5,6-tetrafluorophenyl)]-2-O-3,5-di-Bu t -C 6 H 2 } 2 /MAO in a Nefras medium and in toluene are presented. The catalytic system provides ultrahigh-molecular-weight polyethylene and incorporation of comonomer units at a level of 2–3 mol.% in both solvents. Nascent copolymers formed in Nefras (petroleum solvent), unlike those obtained in toluene, are characterized by two melting peaks in the DSC thermograms and only one when obtained in toluene. The molecular weight of polyolefins is efficiently controlled by the introduction of hydrogen into the system.

A new method for preparation of zirconium and hafnium phenoxyimine complexes L 2 MCl 2 (L is N -(3,5-di- tert -butylsalicylidene)-2,3,5,6-tetrafluoroanilinate anion, M = Zr, Hf) by the solid state interaction of N -(3,5-di- tert -butylsalicylidene)-2,3,5,6-tetrafluoroaniline, the corresponding metal chlorides, and sodium hydride under mechanical activation followed by heating of the activated mixture was developed. The obtained complexes have a high catalytic activity in the reaction of ethylene polymerization.

Experimental data on ethylene homo- and copolymerization with higher a-olefins (hex-1-ene, oct-1-ene, and dec-1-ene) by the catalytic system TiCl2{η2-1-[C(H)=N(2,3,5,6-tetrafluorophenyl)]-2-O-3,5-di-But-C6H2}2/MAO in a Nefras medium and in toluene are presented. The catalytic system provides ultrahigh-molecular-weight polyethylene and incorporation of comonomer units at a level of 2–3 mol.% in both solvents. Nascent copolymers formed in Nefras (petroleum solvent), unlike those obtained in toluene, are characterized by two melting peaks in the DSC thermograms and only one when obtained in toluene. The molecular weight of polyolefins is efficiently controlled by the introduction of hydrogen into the system.

Catalytic properties of the phenoxyimine zirconium complexes, viz. , bis[ N -(3,5-di- tert -butylsalicylidene)anilinato]zirconium(IV) dichloride ( 1 ) and its fluorinated analog, bis[ N -(3,5-di- tert -butylsalicylidene)-2,3,5,6-tetrafluoroanilinato]zirconium(IV) dichloride ( 2 ), were studied. Ethylene homopolymerization and copolymerization of ethylene with α-olefins were chosen as catalytic reactions, and various organoaluminum compounds served as activators: commercial polymethylalumoxane (MAO) containing ∼35 mol.% of trimethylaluminum (TMA), MAO purified from TMA (“dry” MAO), and “classical” organoaluminum compounds, namely, TMA and triisobutylaluminum (TIBA). Complex 1 is not activated by “dry” MAO but is efficiently transformed into the catalytically active state by commercial MAO, “conventional” TMA, and TIBA. These processes give low-molecular-weight polyethylenes (PE) characterized by high values of polydispersity indices and by polymodal curves of gel permeation chromatography (GPC). The order of decreasing the efficiency of activation for the cocatalysts is MAO > TIBA > TMA. Fluorinated complex 2 exhibits a high activity after its treatment with MAO and “dry” MAO, the activity is much lower upon mixing with TIBA, and complex 2 is inactive when using TMA. In the copolymerization of ethylene with hex-1-ene and dec-1-ene, complex 1 treated with MAO is highly active but gives a low level of insertion of the comonomer (1–2 mol.% in the copolymer). Complex 2 activated with “dry” MAO is more efficient in the copolymerization of ethylene with propylene or hex-1-ene but, like complex 1 , it does not produce copolymers with a high content of the comonomer. The both catalysts provide the insertion of α-olefin as isolated units separated by extended sections of the chain consisting of ethylene units.

The effect of trimethylaluminum in commercial methylaluminoxane on the molecular-mass characteristics of polyethylene formed with the phenoxyimine titanium catalyst bis[N-(3,5-di-tert-butylsalicylidene)-2,3,5,6-tetrafluoroanilinato]titanium(IV) dichloride activated by methylaluminoxane of varying purity is studied. It is shown that, all other conditions being equal, an increase in the content of trimethylaluminum in the reaction solution leads to an appreciable decrease in the molecular mass of the polymer. With an increase in the time of polymerization, the molecular mass tends to increase, while overall polydispersity indexes M w/M n remain substantially less than 2. The causes of the above effects are discussed.