Molecular Orbital and IMOMM Studies of the Chain Transfer Mechanisms of the Diimine−M(II)-Catalyzed (M = Ni, Pd) Ethylene Polymerization Reaction

1998 ◽  
Vol 17 (9) ◽  
pp. 1850-1860 ◽  
Author(s):  
Djamaladdin G. Musaev ◽  
Robert D. J. Froese ◽  
Keiji Morokuma
Keyword(s):  
Molecular Orbital ◽  
Ethylene Polymerization ◽  
Chain Transfer ◽  
Polymerization Reaction ◽  
Transfer Mechanisms

Ethylene Oligomerization Catalyzed by a Unique Phosphine−Oxazoline Palladium(II) Complex. Propagation and Chain Transfer Mechanisms

2007 ◽  
Vol 26 (5) ◽  
pp. 1261-1269 ◽  
Author(s):  
Mark D. Doherty ◽  
Stéphane Trudeau ◽  
Peter S. White ◽  
James P. Morken ◽  
Maurice Brookhart
Keyword(s):  
Chain Transfer ◽  
Ethylene Oligomerization ◽  
Complex Propagation ◽  
Transfer Mechanisms

(Pyrazol-1-yl)carbonyl palladium complexes as catalysts for ethylene polymerization reaction

2013 ◽  
Vol 724 ◽  
pp. 95-101 ◽  
Author(s):  
Hosana D. Mkoyi ◽  
Stephen O. Ojwach ◽  
Ilia A. Guzei ◽  
James Darkwa
Keyword(s):  
Ethylene Polymerization ◽  
Palladium Complexes ◽  
Polymerization Reaction

scholarly journals Visible Light-Controlled Living Cationic Polymerization of Methoxystyrene

2021 ◽  
Author(s):  
Lei Wang ◽  
Shaodong Zhang ◽  
Yongfeng Zhou ◽  
Yupo Xu ◽  
Quan Zuo ◽  
...  
Keyword(s):  
Visible Light ◽  
Cationic Polymerization ◽  
Molar Mass ◽  
Chain Transfer ◽  
Polymerization Reaction ◽  
Great Success ◽  
Living Cationic Polymerization ◽  
Green Led ◽  
Polymerization System ◽  
Lytic System

Photo-controlled living polymerization has received great attention in recent years. However, despite the great success therein, the report on photo-controlled living cationic polymerization has been greatly limited. We demonstrate here a novel decolorable, metal-free and visible light-controlled living cationic polymerization system by using tris(2,4-dimethoxyphenyl)methylium tetrafluoroborate as the photocatalyst and phosphate as the chain transfer agent (CTA) for polymerization of 4-methoxystyrene. This polymerization reaction under green LED light irradiation shows clear living characteristics including predictable molar mass, narrow molar-mass dispersity (Đ = 1.25), and sequential polymerization capability. In addition, the photocata-lytic system exits excellent “on-off” photo switchability and shows the longest “off period” of 36 h up to now for photo-controlled cationic polymerization. Furthermore, the residual photo-catalyst is easily deactivated and decolored with addition of a base after the polymerization.

scholarly journals Effects of Various Mixed Metal Chlorides- AlCl3 in TiCl4/MgCl2/THF Catalytic System on Ethylene Polymerization

2015 ◽  
Vol 14 (2) ◽  
pp. 12
Author(s):  
Nittaya Sudsong ◽  
Wanna Phiwkliang ◽  
Bunjerd Jongsomjit ◽  
Piyasan Praserthdam
Keyword(s):  
Catalytic System ◽  
Ethylene Polymerization ◽  
Catalyst System ◽  
Polymerization Reaction ◽  
Molar Ratio ◽  
Metal Chlorides ◽  
Mixed Metal ◽  
Icp Analysis ◽  
Co Addition

In this research, the modification of TiCl4/MgCl2/THF catalyst system with various metal chlorides was investigated on ethylene polymerization. Experimentally, metal chlorides (CaCl2, FeCl2 and ZnCl2) were simultaneously introduced different with TiCl4/MgCl2/THF catalyst. ICP analysis was used to determine the total amount of each metal in the catalyst. For polymerization reaction, TEA was used as cocatalyst and hexane was used as a medium solvent. The Al/Ti molar ratio was 140. The activity result of Ca-Al, Zn-Al and Fe-Al was 979, 1009 and 1476 kgPE/molTi.h, respectively. The coaddition of AlCl3 and FeCl2 in TiCl4/MgCl2/THF catalyst system exhibited the highest activity. It suggested that the co-addition of AlCl3 and FeCl2 has higher electronegativity (EN) and the radius of Fe2+ is closer to Mg2+ resulting in an increased efficiency of the THF removal. This result led to improve the catalyst performance.

Study the Influences of ZnEt2 on Ethylene Chain Transfer Polymerization

2012 ◽  
Vol 602-604 ◽  
pp. 672-675
Author(s):  
An Guo Xiao ◽  
Shi Biao Zhou ◽  
Qing Yun Zheng ◽  
You Ming Shen ◽  
Yong Bin Zhuan
Keyword(s):  
Ethylene Polymerization ◽  
Nickel Complex ◽  
Chain Transfer ◽  
Ion Pairs ◽  
Catalyst System ◽  
Chain Propagation ◽  
Polymerization Mechanism ◽  
System 1 ◽  
Chain Transfer Polymerization

The influences of ZnEt2 on ethylene chain transfer polymerization were investigated in detail and the polymerization mechanism was thoroughly analyzed. The results indicated that ZnEt2 contributed greatly to increase the activity of α-diimine nickel complex/ZnEt2/MAO(MAO: methylaluminoxane). It was striking that α-diimine nickel complex/ZnEt2 catalyst system (1/100 mol/mol) exhibited 8.0 ×104g/mol∙h activity, it was possible the formation of the ion pairs of Nickel and Zinc was convenient for ethylene chain propagation, however, the ion pairs were unstable in ethylene polymerization.

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