Synthesis of atactic polypropylene: Propylene polymerization reactions with TiCl₄–Al(C₂H₅)₂Cl/Mg(C₄H₉)₂ catalyst

Abstract

The Ziegler catalyst, a combination of TiCl4 and Al(C2H5)2Cl, is a very poor catalyst for propylene polymerization. However, the addition of Mg(C4H9)2 to the Ziegler catalyst at a [Mg]:[Al] molar ratio < 0.5 leads to the formation of a potent catalyst system for homopolymerization of propylene. Polymers produced with the TiCl4–Al(C2H5)2Cl/Mg(C4H9)2 catalyst are mostly atactic and amorphous, their minor partially crystalline isotactic components constitute merely 5–10% of the combined polymer material. Principal advantages of the TiCl4–Al(C2H5)2Cl/Mg(C4H9)2 catalyst for the manufacture of atactic PP include high activity, low cost, and the ease of use: the catalyst is prepared in situ from three commercially available components. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47692.

Efficient synthesis of thermoplastic elastomeric amorphous ultra-high molecular weight atactic polypropylene (UHMWaPP)

“…30 Increasing the MAO loading resulted in increased polymerisation activities up to a maximum value at 2500 equivalents of 12 000 and 11 000 kg PP mol Ti −1 h −1 bar −1 for 2 sMAO and 2 respectively. This activity compares well with some of the most active polypropylene catalysts in literature: the TiCl 4 –Al/Mg system reported by Rishina et al and the fluorenyl zirconocene reported by Resconi et al have activities of 22 000 and 29 000 kg PP mol −1 h −1 respectively when used in liquid propylene, 7,53 a far greater concentration of monomer than the 2 bar pressure used in this work. 54 Runs were attempted using 2 and other alkyl aluminium cocatalysts – TMA, TEA, and TIBA – in place of MAO, but negligible activity was recorded in these cases.…”

Application and Suitability of Polymeric Materials as Insulators in Electrical Equipment

“…These different catalysts produce different microstructures of syndiotactic PP with different crystallization behavior and properties through different polymerization mechanisms. Atactic polypropylene can also be produced selectively using metallocene catalysts, atactic polypropylene produced this way has a considerably higher molecular weight [62,63].…”

Ethylene polymerization and copolymerization reactions with Ti(OR)4 – Al2(C2H5)3Cl3/Mg(C4H9)2 catalyst

“…We found earlier that combinations of chloro‐organoaluminium compounds AlR 2 Cl and organomagnesium compounds MgR′ 2 , when used at an [Al]:[Mg] molar ratio above 2, are universal cocatalysts for converting various types of transition metal compounds into alkene polymerization catalysts, including TiCl 4 , 9,10 common heterogeneous and supported Ti‐based catalysts, 11 metallocene complexes 12 and many post‐metallocene complexes 11–17 …”