scholarly journals Enhanced ‘in situ’ catalysis via microwave selective heating: catalytic chain transfer polymerisation

RSC Advances ◽  
2014 ◽  
Vol 4 (31) ◽  
pp. 16172-16180 ◽  
Author(s):  
Kevin Adlington ◽  
Robert McSweeney ◽  
Georgios Dimitrakis ◽  
Samuel W. Kingman ◽  
John P. Robinson ◽  
...  
Keyword(s):  
Microwave Heating ◽  
Chain Transfer ◽  
Active Catalyst ◽  
Selective Heating ◽  
Catalytic Chain Transfer ◽  
Synthesis Methodology ◽  
In Situ Catalysis

The formation of a CCTP active catalyst, which is promoted by adopting microwave heating and an “in situ” synthesis methodology.

Dialkoxy-Substituted, C1-Symmetric Metallocenes: Synthesis and Catalytic Behavior in the Propylene Polymerization Reaction

2004 ◽  
Vol 59 (2) ◽  
pp. 233-240 ◽  
Author(s):  
Martin Schlögl ◽  
Bernhard Rieger
Keyword(s):  
Chain Transfer ◽  
Active Catalyst ◽  
Propylene Polymerization ◽  
Polymerization Reaction ◽  
Catalytic Behavior ◽  
Molecular Weights ◽  
Hydrocarbon Solvents ◽  
In Situ Activation ◽  
Reversible Chain Transfer

The synthesis of a series of C1-symmetric metallocene complexes rac-[1-(5,6-dialkoxy-2-methyl- 1-η5-indenyl)-2-(9-η5-fluorenyl)ethane]zirconium dichlorides (alkyl: n-butyl, n-hexyl, n-octyl, n-decyl) is described. These complexes are versatile catalysts in the polymerization of propylene after in situ activation with triisobutylaluminum (TIBA) and Ph3C[B(C6F5)4] in toluene and heptane solution. All catalysts show higher solubility and improved polymerization properties in industrially used hydrocarbon solvents (e.g. heptane). However, the molecular weights and isotacticity values of the resulting polypropylene materials are decreased compared to the ethoxy-bridged analogue rac- [1-(5,6-ethylenedioxy-2-methyl-η5-indenyl)-2-(9-η5-fluorenyl)ethane]zirconium dichloride. A possible explanation is based on enhanced interaction of the active catalyst centers with Al(III) scavenger molecules even at low Al : Zr ratios, leading to reversible chain transfer.

Direct ‘in situ’, low VOC, high yielding, CO2expanded phase catalytic chain transfer polymerisation: towards scale-up

2013 ◽  
Vol 42 (1) ◽  
pp. 127-136 ◽  
Author(s):  
Kevin Adlington ◽  
Anthony Green ◽  
Wenxin Wang ◽  
Steven M. Howdle ◽  
Derek J. Irvine
Keyword(s):  
Chain Transfer ◽  
Scale Up ◽  
Catalytic Chain Transfer
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