✦ LIBER ✦

Distribution of active centres in Ziegler-Natta catalysts based on TiCl3 by their activity and stereospecificity: Catalyst poisoning

✍ Scribed by L.A. Rishina; E.I. Vizen

Publisher: Elsevier Science
Year: 1980
Tongue: English
Weight: 334 KB
Volume: 16
Category: Article
ISSN: 0014-3057
DOI: 10.1016/0014-3057(80)90178-0

No coin nor oath required. For personal study only.

✦ Synopsis

A fractional poisoning method has shown that all groups of Ziegler catalyst centres, both stereospecific and non-stereospecific, have a similar distribution of propagation rate constants. The most regular and highly molecular isotactic fraction is quite uniform by stereoregularity. Most of the poisonresistable part of active centres in ~STiCI3-AIEt 3 systems have properties similar to those of initial system TiCI3-AIEt2CI, which may be caused by different adsorption abilities of co-catalysts AIEt3 and AIEt2CI at TiCI3 surface. Values np and/~p have been estimated for 6TiCI3(TACI-AIEh system.

📜 SIMILAR VOLUMES

Stereospecific Nature of Active Sites on

Stereospecific Nature of Active Sites on TiCl4/MgCl2 Ziegler–Natta Catalyst in the Presence of an Internal Electron Donor

✍ Boping Liu; Takashi Nitta; Hisayuki Nakatani; Minoru Terano 📂 Article 📅 2003 🏛 John Wiley and Sons 🌐 English ⚖ 127 KB 👁 1 views

## Abstract Based on our previous study on the donor‐free TiCl~4~/MgCl~2~ catalyst, the stereospecific nature of active sites on this catalyst after the addition of an internal donor, ethylbenzoate (EB), was investigated by stopped‐flow propylene polymerization combined with temperature rising elut

Effects of MgCl2 Crystallographic Struct

Effects of MgCl2 Crystallographic Structure on Active Centre Formation in Immobilized Single-Centre and Ziegler–Natta Catalysts for Ethylene Polymerization

✍ Rubin Huang; Federica Malizia; Gianni Pennini; Cor E. Koning; John C. Chadwick 📂 Article 📅 2008 🏛 John Wiley and Sons 🌐 English ⚖ 261 KB

## Abstract The ability of a MgCl~2~ support to activate a transition metal catalyst has been found to depend both on the crystallographic structure of the support and on the nature of the catalyst. A high degree of crystallographic disorder can be very effective for the immobilization and activati

Structure of active centers, their stere

Structure of active centers, their stereospecificity distribution, and multiplicity in diene polymerization initiated by NdCl3-based catalytic systems

✍ V. N. Urazbaev; V. P. Efimov; Z. M. Sabirov; Yu. B. Monakov 📂 Article 📅 2003 🏛 John Wiley and Sons 🌐 English ⚖ 62 KB 👁 1 views

Distribution of the centers with respect

Distribution of the centers with respect of activity and stereospecificity and their chemical nature in the catalytic system δ-TiCl3/AlEt3 and the possibility to affect them by addition of donors

✍ A. A. Rišina; E. I. Vizen; F. S. D'Jačkovskij 📂 Article 📅 1983 🏛 John Wiley and Sons 🌐 English ⚖ 468 KB 👁 2 views

TiCl4/MgH2-supported Ziegler-type cataly

TiCl4/MgH2-supported Ziegler-type catalyst system, 4. The influence of 14CO contact time and mole ratio Al(C2H5)3/Ti on concentration of active sites in ethylene homo- and copolymerization

✍ Isam A. Jaber; Gerhard Fink 📂 Article 📅 1994 🏛 John Wiley and Sons 🌐 English ⚖ 544 KB

## Abstract The effect of varying ^14^CO contact time upon the concentration of active centres __C__\* in ethylene homopolymerization using the TiCl~4~/MgH~2~ · Al(C~2~H~5~)~3~ catalytic system shows that the polymer radioactivity, and hence __C__\*, increase sharply in the first sixty minutes of ^