Results 181 to 190 of about 2,112 (213)

Olefin Polymerization with Metallocene Catalysts

2014
This chapter firstly explains the basic terms and concepts concerning olefin polymerization and polymer synthesis, and then provides comprehensive yet concise commentaries on olefin polymerization by metallocene catalysts. In Sect. 1.1 (Introduction), the history of olefin polymerization catalysts is briefly reviewed with a focus on the uniformity of ...
openaire   +1 more source

New polyolefins by metallocene catalysts

Pure and Applied Chemistry, 1998
Abstract
openaire   +1 more source

Metallocene Catalysts in Dispersed Media

1997
Metallocene catalysts are organometallic coordination compounds in which one or two cyclopentadienyl rings or substituted cyclopentadienyl rings are bonded to a central transition metal atom, as shown in Figure1. The nature and number of the rings and substituents (S), the type of transition metal (M) and its substituents (R), the type of the bridge ...
J. B. P. Soares, A. E. Hamielec
openaire   +1 more source

Copolymerization of ethylene and ?-olefins with combined metallocene catalysts. II. Mathematical modeling of polymerization with single metallocene catalysts

Journal of Polymer Science Part A: Polymer Chemistry, 2000
The relation between the polymerization conditions and the distributions of molecular weight (MWD) and chemical composition (CCD) of poly(ethylene-co-1-hexene) made with single supported metallocene catalysts was investigated. Understanding the behavior of each metallocene under different polymerization conditions is necessary for designing combined ...
Jung Dae Kim, João B. P. Soares
openaire   +1 more source

New application for metallocene catalysts in olefin polymerization

Dalton Transactions, 2009
Metallocenes and other transition metal complexes, activated by methylaluminoxane allow the synthesis of polyolefins with a highly defined microstructure, tacticity, and stereoregularity. New copolymers, long chain branched polymers, and polyolefin nanocomposites are produced by these highly active catalysts.
Walter, Kaminsky, Andreas, Funck, Heinrich, Hähnsen   +2 more
openaire   +2 more sources

A Metallocene-Pyrrolidinopyridine Nucleophilic Catalyst for Asymmetric Synthesis

Organic Letters, 2006
[reaction: see text] A highly active chiral 4-aminopyridine nucleophilic catalyst, available in three steps from (S,S)-hexane-2,5-diol, was applied to the asymmetric Steglich rearrangement of O-aceylated azlactones (1 mol % loading, up to 76% ee).
Huy V, Nguyen, David C D, Butler, Christopher J, Richards   +2 more
openaire   +2 more sources

Olefin copolymerization with metallocene catalysts. I. Comparison of catalysts

Journal of Polymer Science Part A: Polymer Chemistry, 1991
AbstractA number of metallocene/methylaluminoxane (MAO) catalysts have been compared for ethylene/propylene copolymerizations to find relationship between the polymerization activities, copolymer structures, and copolymerization reactivity ratio with the catalyst structures.
James C. W. Chien, Dewei He
openaire   +1 more source

Metallocene catalysts technology and environment

Comptes Rendus de l'Académie des Sciences - Series IIC - Chemistry, 2000
Abstract The polyolefin industry is increasingly confronted with the challenge to meet restricting environmental regulations. In parallel, the environmentally conscious public opinion (customer!), now globally organized, demands even more stringent anticipative actions to prevent any short or long term damages inflicted upon environment.
openaire   +1 more source

Catalyst comprising a metallocene complex and a co-catalyst

2016
The invention relates to a metallocene complex, I (M = metal selected from lanthanides or transition metals from group 3, 4, 5 or 6 of the Periodic System of the Elements; Q = anionic ligand to M, k is the no. of Q groups and equals the valence of M minus 2, R = bridging group contg. at least one carbon atom bonded to the indenyl moiety at 2-​position;
Vadake Kulangara, S., Friederichs, N., Ginzburg, A., Rongo, L., Voskoboynikov, A., Izmer, V., Kononovich, D., Samsonov, O., Shaikh, A. A. G., BUSICO, VINCENZO, CIPULLO, ROBERTA, Borisov, I., Chatterjee, A., Uborsky, D.   +13 more
openaire   +1 more source

Catalyst comprising a metallocene complex and a co-catalyst

2017
The invention relates to a metallocene complex according to formula I or II wherein M is a metal selected from lanthanides or transition metals from group 3, 4, 5 or 6 of the Periodic System of the Elements, Q is an anionic ligand to M, k is the no. of Q groups and equals the valence of M minus 2, R is a divalent bridging group, R1, R2, R3 and R4 are ...
Vadake Kulangara, S., Friederichs, N. H., Ginzburg, A., Voskoboynikov, A., Izmer, V., Kononovich, D., Samsonov, O., VITTORIA, ANTONIO, BUSICO, VINCENZO, CIPULLO, ROBERTA   +9 more
openaire   +1 more source