Part 1 outlines the complex, parallel historical evolution of ZieglerNatta catalysts and related problems. In Part 2, as a general method of inquiry, chemical language and discourse are analyzed, at first to clarify chemists’ epistemic views and the ontological status of catalysts. After analyzing contrasting definitions of ‘catalyst’ and the chemical properties of catalysts, a suitable metapho...

In propylene (C3) polymerization with Ziegler-Natta catalyst, not only internal donor but also external is very important to make isotactic polypropylene (PP) higher yield. Most propylene-based polymers have been commercially produced catalysts combined dialkyl-dialkoxy silane compounds (R2Si(OR)2) such as C-donor, P-donor, and D-donor donors. this paper, we will introduce the performance amino...

Zirconium and Hafnium Ziegler-Natta catalysts containing the [(2,6C12C6H3NCH2CH2)2NMe] ([ArciN2NMe]) ligand were prepared and employed in the polymerization of 1-hexene. Hafnium Ziegler-Natta catalysts containing the [(2,6X2C6H3NHCH2)2C(CH3)(2-C5H4N)] ([Arx2NPy]) (X = Cl or F) ligand were also prepared for use in 1-hexene polymerization studies. Compounds of the type [Ligand]MR 2 (R = Me, i-Bu)...

Models for the likely active catalysts in homogeneous Ziegler-Natta systems have been studied using ab initio quantum chemical methods. We investigated the geometries of the isoelectronic model complexes, X2M-R where X = C1 or Cp = (q5-CsHs); where M = Sc and Ti+ (and also Ti); and where R = H, CH3, or SiH3. The general trend is that the M = Sc compounds strongly prefer a planar configuration, ...

Vanadium-modified (SiO2/MgO/MgCl2)•TiClx Ziegler-Natta catalysts were prepared through co-impregnation of water-soluble magnesium and vanadium salts under different pH values. Several key factors such as pH value of co-impregnation solution during catalyst preparation, catalyst performances including catalytic activity, ethylene/1-hexene copolymerization and hydrogen response were investigated....