Pronounced Enhancement Brought in by Substituents on the Cyclopentadienyl Ligand:  Catalyst System (C5Me4R)2Sm(THF)x/MMAO (R = Et,iPr,nBu, TMS; MMAO = Modified Methylaluminoxane) for 1,4-Cis Stereospecific Polymerization of 1,3-Butadiene in Cyclohexane Solvent

2003 ◽  
Vol 36 (21) ◽  
pp. 7923-7926 ◽  
Author(s):  
Shojiro Kaita ◽  
Yuko Takeguchi ◽  
Zhaomin Hou ◽  
Masayoshi Nishiura ◽  
Yoshiharu Doi ◽  
...  
Keyword(s):  
Catalyst System ◽  
Cyclopentadienyl Ligand ◽  
Stereospecific Polymerization

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.

Kinetic Study on Stereospecific Polymerization of 1,3-Butadiene Using a Nickel Based Catalyst System in Environmentally Friendly Solvent

2012 ◽  
Vol 51 (34) ◽  
pp. 11066-11071 ◽  
Author(s):  
Archana Singh ◽  
Ankur Chavda ◽  
Subrahmanyam Nandula ◽  
Raksh Vir Jasra ◽  
Madhuchhanda Maiti
Keyword(s):  
Kinetic Study ◽  
Environmentally Friendly ◽  
Catalyst System ◽  
Stereospecific Polymerization

Stereospecific polymerization of N-vinylcarbazole by ZnEt2CoCl2-pyridine catalyst system

Polymer ◽  
1981 ◽  
Vol 22 (10) ◽  
pp. 1319-1323 ◽  
Author(s):  
Mukul Biswas ◽  
Girish Chandra Mishra
Keyword(s):  
Catalyst System ◽  
Stereospecific Polymerization

Direct Observation of Chain Lengths and Conformations in Oligofluorene Distributions from Controlled Polymerization by Double Electron-Electron Resonance

2019 ◽  
Author(s):  
Dennis Bücker ◽  
Annika Sickinger ◽  
Julian D. Ruiz Perez ◽  
Manuel Oestringer ◽  
Stefan Mecking ◽  
...  
Keyword(s):  
Chain Length ◽  
Length Distribution ◽  
Catalyst System ◽  
Chain Conformation ◽  
Controlled Polymerization ◽  
Chain Length Distribution ◽  
Electron Resonance ◽  
Double Electron ◽  
The Individual ◽  
Double Electron Electron Resonance

Synthetic polymers are mixtures of different length chains, and their chain length and chain conformation is often experimentally characterized by ensemble averages. We demonstrate that Double-Electron-Electron-Resonance (DEER) spectroscopy can reveal the chain length distribution, and chain conformation and flexibility of the individual n-mers in oligo-(9,9-dioctylfluorene) from controlled Suzuki-Miyaura Coupling Polymerization (cSMCP). The required spin-labeled chain ends were introduced efficiently via a TEMPO-substituted initiator and chain terminating agent, respectively, with an in situ catalyst system. Individual precise chain length oligomers as reference materials were obtained by a stepwise approach. Chain length distribution, chain conformation and flexibility can also be accessed within poly(fluorene) nanoparticles.

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