Study of propylene polymerization catalyzed by a spherical MgCl2-supported Ziegler-Natta catalyst system: The effects of external donors

2004 ◽  
Vol 95 (3) ◽  
pp. 738-742 ◽  
Author(s):  
Zhenli Ma ◽  
Li Wang ◽  
Wenqin Wang ◽  
Lianfang Feng ◽  
Xueping Gu
Keyword(s):  
Catalyst System ◽  
Propylene Polymerization ◽  
Natta Catalyst ◽  
Ziegler Natta Catalyst

Influences of silane/ether composite external donors on propylene polymerization with MgCl2-supported Ziegler-Natta catalyst in the presence of hydrogen

e-Polymers ◽  
2011 ◽  
Vol 11 (1) ◽  
Author(s):  
Song-tao Tu ◽  
Jun-qin Lou ◽  
Zhi-sheng Fu ◽  
Zhi-qiang Fan
Keyword(s):  
Molecular Weight ◽  
Catalytic Activity ◽  
High Activity ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Catalyst System ◽  
Propylene Polymerization ◽  
External Donor ◽  
Natta Catalyst ◽  
Ziegler Natta Catalyst

AbstractIn this work, the effects of two silane type external donors, Ph2Si(OCH3)2 (DPDMS) and dicyclopentyldimethoxysilane (DCPDMS) on propylene slurry polymerization in the presence of hydrogen with a MgCl2/TiCl4/DIBP - Al(C2H5)3 catalyst system were investigated, and the tacticity distribution and molecular weight distribution (MWD) of polypropylene (PP) were further regulated by using silane/ether (ROCH3, R = n-Bu, i-C8H17) composite external donors. The tacticity distribution of PP, as revealed by successive self-nucleation and annealing (SSA) thermo analysis of the polymer, is markedly changed by the external donors. DCPDMS shows much stronger effects than DPDMS. Addition of the ether as an auxiliary external donor in MgCl2/TiCl4/DIBP-TEA/silane (DPDMS or DCPDMS) lead to further increase in catalytic activity and isotacticity of PP, and changes in tacticity distribution. By using the composite external donors, PP with both higher isotacticity index, lower molecular weight or narrower molecular weight distribution was prepared at high activity. Effects of the external donors on the active center distribution were discussed based on the results of deconvoluting the MWD curve with multiple Flory “most-probable” distributions, and possible mechanism of the external donor effects was proposed.

Control of Ziegler–Natta catalyst activity by the structural design of alkoxysilane-based external donors

2020 ◽  
Vol 44 (17) ◽  
pp. 6845-6852 ◽  
Author(s):  
Vikas Khatri ◽  
Usharani Sahoo ◽  
Sukhdeep Kaur ◽  
Rashmi Rani ◽  
Gurmeet Singh ◽  
...  
Keyword(s):  
Structural Design ◽  
Catalyst Activity ◽  
Propylene Polymerization ◽  
Natta Catalyst ◽  
Ziegler Natta Catalyst

Herein, the evaluation of four commercial alkoxysilanes and two laboratory synthesized novel diethoxysilacycloalkanes as external donors towards propylene polymerization has been done.

scholarly journals Investigation of a Ziegler–Natta catalyst system derived from a mixture of lithium tetraalkylaluminate, aluminum chloride, and titanium tetrachloride and its usefulness in polymerizations involving styrene

1981 ◽  
Vol 59 (10) ◽  
pp. 1425-1432 ◽  
Author(s):  
Anu Mishra
Keyword(s):  
Aluminum Chloride ◽  
Titanium Tetrachloride ◽  
Active Catalyst ◽  
Catalyst System ◽  
Active Components ◽  
Vinyl Ethers ◽  
Natta Catalyst ◽  
Stereospecific Polymerization ◽  
Derivatives Of ◽  
Ziegler Natta Catalyst

Vinyl ethers, 1-olefins, and styrene were homo- and copolymerized by the use of catalyst derived from a mixture of lithium tetraalkylaluminate (LiAlR4), aluminum chloride (AlCl3), and titanium tetrachloride (TiCl4), in order to determine the nature of the active components present.It is postulated that the active catalyst in the stereospecific polymerization of vinyl ethers is ether-coordinated TiCl3•LiCl, while in the polymerization of 1-olefins and styrene, it is the alkylated derivatives of TiCl3•LiCl.For homo- and copolymerization of styrene, AlR3 seems to be the preferred alkylating agent. About 3 to 4 equivalents of AlR3 are needed for complete alkylation of TiCl3•LiCl, probably due to heterogeneity of the system.Highly isotactic polystyrene and copolymers of styrene with 1-olefins can be prepared in good yields by the use of this catalyst.

Synthesizing UHMWPE Using Ziegler-Natta Catalyst System of MgCl2(ethoxide type)/ TiCl4/tri-isobutylaluminum

2008 ◽  
Vol 274 (1) ◽  
pp. 148-153 ◽  
Author(s):  
Roghieh Jamjah ◽  
Gholam Hossein Zohuri ◽  
Mohsen Javaheri ◽  
Mehdi Nekoomanesh ◽  
Saeid Ahmadjo ◽  
...  
Keyword(s):  
Catalyst System ◽  
Natta Catalyst ◽  
Ziegler Natta Catalyst

POISONING OF ACTIVE SITES ON ZIEGLER-NATTA CATALYST FOR PROPYLENE POLYMERIZATION

2008 ◽  
Vol 26 (05) ◽  
pp. 547 ◽  
Author(s):  
Kitti Tangjituabun ◽  
Sang Yull Kim ◽  
Yuichi Hiraoka ◽  
Toshiaki Taniike ◽  
Minoru Terano ◽  
...  
Keyword(s):  
Active Sites ◽  
Propylene Polymerization ◽  
Natta Catalyst ◽  
Ziegler Natta Catalyst
Sign in / Sign up

Export Citation Format

Share Document