Interaction between Two Active Sites of the Same Catalyst for Macromonomer Enchained Olefin Polymerization

2017 ◽  
Vol 50 (23) ◽  
pp. 9151-9161 ◽  
Author(s):  
Thilina Gunasekara ◽  
Jungsuk Kim ◽  
Silei Xiong ◽  
Andrew Preston ◽  
D. Keith Steelman ◽  
...  
Keyword(s):  
Active Sites ◽  
Olefin Polymerization

scholarly journals Research Progress of Pre - transition Metal Olefin Polymerization Catalyst for Salicylaldehyde Imine

2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Lulu Hou ◽  
Hongyu Ren ◽  
Baoli Guo
Keyword(s):  
Transition Metal ◽  
Active Sites ◽  
Olefin Polymerization ◽  
Product Distribution ◽  
Catalytic Performance ◽  
Industrial Applications ◽  
Research Progress ◽  
Metal Catalyst ◽  
Transition Metal Catalyst ◽  
Polymerization Catalyst

Salicylaldehyde imine transition metal catalyst is a kind of olefin polymerization catalyst which is widely used in the coordination of salicylaldehyde imine ligand and pre-transition metal. Salicylaldehyde imine ligands have the characteristics of easily insert different substituents via organic synthesize. Therefore, the regulation of the polymerization activity, polymerization product and product distribution can be achieved by changing the steric hindrance effect, electronic effect and the number of metal active sites which near the catalytic active center. The development status of the transition metal catalyst of salicylaldehyde imide was summarized in this paper. The influence of the ligand structure of salicylaldehyde imide transition metal catalyst on the catalytic performance which involved the high selectivity ethylene trimerization, ethylene / α-olefin, / Polar monomer copolymerization, ethylene polymerization production of ultra-high molecular weight polyethylene and many other areas of olefin polymerization was elaborated and providing references for further study and industrial applications of this catalyst.

scholarly journals Development of Large-Scale Stopped-Flow Technique and its Application in Elucidation of Initial Ziegler–Natta Olefin Polymerization Kinetics

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1012 ◽  
Author(s):  
Ashutosh Thakur ◽  
Toru Wada ◽  
Patchanee Chammingkwan ◽  
Minoru Terano ◽  
Toshiaki Taniike
Keyword(s):  
Active Sites ◽  
Large Scale ◽  
Olefin Polymerization ◽  
Polymerization Kinetics ◽  
Propylene Polymerization ◽  
Time Range ◽  
Stopped Flow ◽  
Chemical Transformations ◽  
Polymerization Catalysis ◽  
Short Period

The stopped-flow (SF) technique has been extensively applied to study Ziegler–Natta (ZN) olefin polymerization kinetics within an extremely short period (typically <0.2 s) for understanding the nature of the active sites as well as the polymerization mechanisms through microstructure analyses of obtained polymers. In spite of its great applicability, a small amount of polymer that is yielded in a short-time polymerization has been a major bottleneck for polymer characterizations. In order to overcome this limitation, a large-scale SF (LSF) system has been developed, which offers stable and scalable polymerization over an expanded time range from a few tens milliseconds to several seconds. The scalability of the LSF technique has been further improved by introducing a new quenching protocol. With these advantages, the LSF technique has been effectively applied to address several unknown issues in ZN catalysis, such as the role of physical and chemical transformations of a catalyst on the initial polymerization kinetics, and regiochemistry of ZN propylene polymerization. Here, we review the development of the LSF technique and recent efforts for understanding heterogeneous ZN olefin polymerization catalysis with this new system.

Determination of the Number of Active Sites for Olefin Polymerization Catalyzed over Metallocene/MAO Using the CO Inhibition Method

1996 ◽  
Vol 29 (23) ◽  
pp. 7305-7309 ◽  
Author(s):  
Taek Kyu Han ◽  
Young Soo Ko ◽  
Je Woo Park ◽  
Seong Ihl Woo
Keyword(s):  
Active Sites ◽  
Olefin Polymerization
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