Ethylene/propylene copolymerization over three conventional C2-symmetric metallocene catalysts: Correlation between catalyst configuration and copolymer microstructure

2010 ◽  
Vol 118 (6) ◽  
pp. 3218-3226 ◽  
Author(s):  
Li Lu ◽  
Hui Niu ◽  
Jin-Yong Dong ◽  
Xutao Zhao ◽  
Xuteng Hu
Keyword(s):  
Metallocene Catalysts ◽  
Ethylene Propylene ◽  
Copolymer Microstructure

Terpolymerization of Ethylene/Propylene/Diene Monomers Using (2-PhInd)2ZrCl2 Metallocene Catalysts

2010 ◽  
Vol 4 (11-12) ◽  
pp. 707-714 ◽  
Author(s):  
Saeid Ahmadjo ◽  
Hassan Arabi ◽  
Mehdi Nekoomanesh ◽  
Gholam Hossein Zohuri ◽  
Mohammad Mehdi Mortazavi ◽  
...  
Keyword(s):  
Metallocene Catalysts ◽  
Ethylene Propylene

Synthesis and Characterization of Low Molecular Weight Ethylene-Propylene Copolymers Prepared Using Metallocene Catalysts

2014 ◽  
Vol 8 (12) ◽  
pp. 796-804
Author(s):  
Kenda Tourkmani ◽  
Emilio Casas ◽  
Beatriz Paredes ◽  
Jovita Moreno ◽  
Ponciano Perez ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Synthesis And Characterization ◽  
Low Molecular Weight ◽  
Metallocene Catalysts ◽  
Ethylene Propylene

Study of Ethylene-Propylene-1-Hexene Co- and Terpolymers Obtained with Homogeneous and Supported Metallocene Catalysts

2006 ◽  
Vol 245-246 (1) ◽  
pp. 42-50 ◽  
Author(s):  
Griselda Barrera Galland ◽  
João Henrique Zimnoch dos Santos ◽  
Maiara Dall'Agnol ◽  
Rubens Bisatto
Keyword(s):  
Metallocene Catalysts ◽  
Ethylene Propylene

Contribution to the Study of Ethylene-Propylene Copolymers by Infrared Spectroscopy. Distribution of Monomeric Units

1965 ◽  
Vol 38 (2) ◽  
pp. 334-342 ◽  
Author(s):  
Giovanni Bucci ◽  
Tonino Simonazzi
Keyword(s):  
Infrared Spectroscopy ◽  
Numerical Evaluation ◽  
Distribution Functions ◽  
Reactivity Ratios ◽  
Block Polymers ◽  
Ethylene Propylene ◽  
Copolymer Microstructure ◽  
Catalyst Systems ◽  
Random Alternation ◽  
Theoretical Considerations

Abstract Elastomeric properties of ethylene-propylene copolymers depend not only on the composition but also on the copolymer microstructure, i.e., on the distribution of monomeric units along the macromolecular chain. According to Natta and coworkers the best polymer should be obtained when two monomeric units are randomly alternated in the macromolecule. The random alternation of the monomers is actually only partial because somewhat longer homosequences are formed. In such a case one deals with block polymers. On the basis of some theoretical considerations on the copolymerization process and also on the basis on the reactivity ratios of the two monomers, Natta and coworkers have calculated the distribution functions of sequences for various catalyst systems. Infrared spectroscopy has been widely used in connection with this problem though from different viewpoints and with different aims. The purpose of our work is to reanalyze the whole problem. We have focused our attention on the CH2 rocking band in the sequence (—CH2—)n, where n varies from 1 to 5 or more. Some disagreement exists between various authors on the assignment of these bands, especially in the case of the (—CH2—)3 and (—CH2—)4 sequences. We have then divided our work as follows: (a) assignment of infrared bands in the spectral region between 900 and 650 cm−1; (b) calculation of absorbances at various frequencies; (c) attempt at a numerical evaluation of the distribution of monomeric units.

Metallocene Catalysts for Synthesis of Ethylene-Propylene Rubber

2011 ◽  
Vol 38 (4) ◽  
pp. 23-28
Author(s):  
I.A. Arutiunov ◽  
O.L. Ivanis'ko ◽  
P.V. Kostoglodov ◽  
D.A. Maksimov ◽  
A.I. Kochnev ◽  
...  
Keyword(s):  
Metallocene Catalysts ◽  
Ethylene Propylene ◽  
Ethylene Propylene Rubber

scholarly journals Preparation of Half- and Post-Metallocene Hafnium Complexes with Tetrahydroquinoline and Tetrahydrophenanthroline Frameworks for Olefin Polymerization

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1093 ◽  
Author(s):  
Jun Won Baek ◽  
Su Jin Kwon ◽  
Hyun Ju Lee ◽  
Tae Jin Kim ◽  
Ji Yeon Ryu ◽  
...  
Keyword(s):  
Chain Transfer ◽  
Olefin Polymerization ◽  
Ion Pair ◽  
Metallocene Catalysts ◽  
Active Complex ◽  
Ethylene Propylene ◽  
X Ray ◽  
X Ray Crystallography ◽  
Chain Transfer Polymerization ◽  
Metallocene Complexes

Hafnium complexes have drawn attention for their application as post-metallocene catalysts with unique performance in olefin polymerization. In this work, a series of half-metallocene HfMe2 complexes, bearing a tetrahydroquinoline framework, as well as a series of [Namido,N,Caryl]HfMe2-type post-metallocene complexes, bearing a tetrahydrophenanthroline framework, were prepared; the structures of the prepared Hf complexes were unambiguously confirmed by X-ray crystallography. When the prepared complexes were reacted with anhydrous [(C18H37)2N(H)Me]+[B(C6F5)4]−, desired ion-pair complexes, in which (C18H37)2NMe coordinated to the Hf center, were cleanly afforded. The activated complexes generated from the half-metallocene complexes were inactive for the copolymerization of ethylene/propylene, while those generated from post-metallocene complexes were active. Complex bearing bulky isopropyl substituents (12) exhibited the highest activity. However, the activity was approximately half that of the prototype pyridylamido-Hf Dow catalyst. The comonomer incorporation capability was also inferior to that of the pyridylamido-Hf Dow catalyst. However, 12 performed well in the coordinative chain transfer polymerization performed in the presence of (octyl)2Zn, converting all the fed (octyl)2Zn to (polyolefinyl)2Zn with controlled lengths of the polyolefinyl chain.

New Polyolefin Elastomers Containing “Reactive” p-Methylstyrene Units: Preparation by Metallocene Catalysts

1999 ◽  
Vol 72 (2) ◽  
pp. 283-298 ◽  
Author(s):  
T. C. Chung ◽  
H. L. Lu ◽  
S. Hong
Keyword(s):  
Molecular Weight ◽  
Metallocene Catalyst ◽  
The Other ◽  
Metallocene Catalysts ◽  
Scanning Calorimetry ◽  
Ethylene Propylene ◽  
Other Hand ◽  
Wide Range ◽  
Natta Catalyst ◽  
Poly Ethylene

Abstract This paper summarizes the experimental results of three new polyolefin elastomers, i.e., poly(1-octene-co- p-methylstyrene (O-p-MS), poly(ethylene-ter-propylene-ter-p-methylstyrene) (EP-p-MS) and poly(ethylene-ter-1-octene-ter-p-methylstyrene) (EO-p-MS), containing “reactive” p-MS units. Both Ziegler-Natta and metallocene catalysts were used in studying co- and ter-polymerization reactions. In the copolymerization of 1-octene and p-MS, Ziegler-Natta catalyst TiCl3/AlEt3 exhibits higher catalyst reactivity to produce high molecular weight O-p-MS copolymers, containing up to 20 mol % p-MS. However, the copolymers show very broad composition and molecular weight distributions. On the other hand, two EP-p-MS and EO-p-MS terpolymers with narrow molecular weight and composition distributions were prepared by [C5Me4(SiMe2NtBu)]TiCl2 metallocene catalyst with constrained ligand geometry. The sharp glass transition temperature (Tg) with flat baseline in each differential scanning calorimetry (DSC) curve indicates homogeneous terpolymer microstructures. The Tg of EP-p-MS is very sensitive to the terpolymer composition (ethylene/propylene ratio and p-MS content). In the compositions with ideal ethylene/propylene ratio ∼ 55/45, the Tα is almost proportional to the content of p-MS. Only with the concentration of p-MS < 2 mol %, does the EP-p-MS show alow Tg<−45°C. On the other hand, the EO-p-MS system exhibits a low Tg<−50°C in a wide range of copolymer compositions, even ones with relatively high p-MS contents (< 7 mol %).

Sign in / Sign up

Export Citation Format

Share Document