Amorphous atactic polypropylene (PP) with an average molecular weight of 50,000-100,000 is produced by polymerizing propylene with a ternary Ti(Oiso-Pr) 4 -AlEt 2 Cl/MgBu 2 catalyst at 30-50. Main advantages of this catalyst compared with other catalysts capable of nearly exclusively producing atactic PP (such as some heterogeneous Ziegler-Natta, metallocene and postmetallocene catalysts) are high activity, low cost and the ease of use: the catalyst is prepared in situ from three commercially available compounds readily soluble in aliphatic and aromatic hydrocarbons.

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The polymerization of ethylene and propylene and the copolymerization of ethylene and hexene-1 with a Ti(O-iso-Pr) 4 -AlR 2 Cl/MgBu 2 catalyst system have been studied. The advantages of this system over metallocene and postmetallocene catalysts are high activity, low cost, and ease of synthesis. The resulting polymers and copolymers are characterized by a broad molecular-mass distribution, which reflects the heterogeneity of the active sites with respect to kinetic parameters. As a consequence, the ethylene/hexene-1 copolymers exhibit compositional heterogeneity. The active sites of the system produce copolymers with a pronounced tendency toward alternation of monomer units. The propylene polymerization product is mostly amorphous atactic polypropylene.

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The Ziegler catalyst, a combination of TiCl4 and Al(C2H5)2Cl, was widely used since 1950s for the commercial manufacture of linear polyethylene. We found that addition of Mg(C4H9)2 to this catalyst at [Al]:[Mg]molar > 2 leads to the formation of a very active catalyst system for homopolymerization of ethylene and for copolymerization of ethylene and 1‐alkenes. The principal advantages of the ternary TiCl4–Al(C2H5)2Cl/Mg(C4H9)2 catalyst are very high activity (six to seven times higher than the activity of the original Ziegler catalyst), low cost, and the ease of use: the catalyst is prepared in situ from three commercially available cheap compounds soluble in aliphatic and aromatic hydrocarbons. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47340.

Two Ti complexes with bidentate ligands derived from pinacol and perfluoropinacol and activated with a binary Al(C 2 H 5 ) 2 Cl -Mg(C 4 H 9 ) 2 cocatalyst are efficient catalysts for polymerization of lightest alkenes, ethylene and propylene, and for their copolymerization. They produce linear polyethylene of moderate molecular weight and essentially atactic amorphous polypropylene. Ethylene/propylene copolymers prepared with these catalysts are compositionally uniform resins with a very low crystallinity degree which can be used as synthetic EPM rubbers.

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Polymerization reactions of ethylene, propylene, higher 1‐alkenes (1‐hexene, 1‐octene, 1‐decene, vinyl cyclohexane, 3‐methyl‐1‐butene), and copolymerization reactions of ethylene with 1‐octene with a post‐metallocene catalyst containing an oxyquinolinyl complex of Ti and a combination of Al(C2H5)2Cl and Mg(C4H9)2 as a cocatalyst were studied. The catalyst is highly active and, judging by the broad molecular weight distribution of the polymers, contains several active center populations. The active centers differ not only in their kinetic parameters but also in stereospecificity. Most of the active centers produce essentially atactic polypropylene but a small fraction of the centers produces polypropylene of moderate isotacticity degree. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 1844–1854