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Topic: Zieglar-Natta catalyst

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Polymerization - Wikipedia, the free encyclopedia With the new catalysts, the tacticity of the polypropene chain, the alignment of alkyl groups, was also able to be controlled. Instead of a free radical reaction, the initial ethene monomer inserts between the aluminium atom and one of the ethyl groups in the catalyst. Again new catalysts, the metallocenes, were developed to tackle these problems. en.wikipedia.org /wiki/Polymerization   (1267 words)

Cross-copolymerized olefin/aromatic vinyl/diene copolymer and process for producing the same - Patent 6566453 Further, the copolymer to be suitably used in the present invention, is an ethylene/styrene/diene copolymer obtainable by means of a metallocene catalyst capable of producing an isotactic polystyrene by homopolymerization of styrene, and an ethylene/styrene/diene copolymer obtainable by means of a metallocene catalyst capable of producing polyethylene by homopolymerization of ethylene. Particularly preferred is a polymerization catalyst comprising a transition metal compound of the above general formula (1) wherein at least one of A and B is an unsubstituted or substituted benzoindenyl group or an unsubstituted or substituted indenyl group, and a cocatalyst. This single site coordination polymerization catalyst comprising a transition metal compound represented by the general formula (1) and a cocatalyst, is capable of copolymerizing residual coordination polymerizable double bonds of diene units, particularly divinylbenzene, copolymerized to the polymer main chain, at high efficiency, and it is preferred in the present invention. www.freepatentsonline.com /6566453.html   (14135 words)

Process for producing propylene block copolymers - Patent 4433110 In the presence of hydrogen, the first polymerization vessel was supplied continuously with 4.7 g/hr of the TiCl.sub.3 AA catalyst, 10 g/hr of diethylaluminum chloride, 20 l/hr of purified heptane, 5.24 kg/hr of propylene, and 1 kg/hr of butene-1, and copolymerization was conducted at 50.degree. In the presence of hydrogen, the first polymerization vessel was supplied continuously with 4.7 g/hr or the TiCl.sub.3 AA catalyst, 10 g/hr of diethylaluminum chloride, 20 l/hr of purified heptane, 5.5 kg/hr of propylene and 0.16 kg/hr of ethylene, and copolymerization was conducted at 50.degree. The catalyst system made of the transition metal compound and organometallic compound may further contain a third component which is added to the reaction system during the polymerization. www.freepatentsonline.com /4433110.html   (4388 words)

Zieglar-Natta_catalyst Zieglar Natta catalyst homogenous catalyst Heterogeneous catalyst Platinum Catalyst Karl Ziegler Ziegler Natta catalyst Gunter M Ziegler Philip Ziegler Joakim Ziegler Gene Ziegler Ronald L Ziegler Ziegler... Zieglar-Natta catalyst) A Ziegler-Natta catalyst is a catalyst used in the production of unbranched, stereoregular poly alkene polymers. Ziegler-Natta catalysts are typically based on titanium tetrachloride and the organometallic compound triethylaluminium. polyethylene.networklive.org /subgo.php?Zieglar-Natta_catalyst   (218 words)

science what is a catalyst Site Resources Used as a catalyst, initiator, or sensitizer in polymer reactions, and in... We hope you have enjoyed the science what is a catalyst resources online directory, as much as we have enjoyed researching and compiling it for you. ...and aluminum, or reaction with hydrogen bromide in the presence of an aluminum halide catalyst (U.S. Bromoform is used as an... search-now180.com /sites/catalyst/science_what_is_a_catalyst.html   (570 words)

Untitled This project is aimed at the discovery of new methods for the generation of acyl derivatives through the use of carbon monoxide and transition metal catalysts. Another alternative is to attempt the same type of coupling chemistry using a heterogeneous catalyst, such as palladium on charcoal or nickel chloride on alumina. It should also be possible to extract the catalyst into an aqueous layer while separating the product in an organic layer by choosing the appropriate ligands on the catalyst. www.chem.rochester.edu /~wdjgrp/nsfb9/nsfb9.html   (3952 words)

World Intellectual Property Organization The polymerization catalyst or catalyst (s) of the invention, in liquid form may be fed with an activator together or separately to a reactor using the injection methods described in PCT publication WO 97/46599, which is fully incorporated herein by reference. While most of the publications discussed herein refer to a bulky ligand metallocene catalyst, it is contemplated that the activators and activation methods utilized for these bulky ligand metallocene compounds are applicable to the ruthenium complex and phosphorous containing ligand catalyst compositions, and to the phosphorous containing ruthenium complex catalyst compositions of this invention. In one embodiment, the invention is directed to a catalyst composition including a ruthenium complex and a phosphorous containing ligand, a catalyst system including the catalyst composition, and to its use in the polymerization of olefin (s). www.wipo.int /ipdl/IPDL-CIMAGES/view/pct/getbykey5?KEY=01/83569.011108&ELEMENT_SET=DECL   (6973 words)

Medical Device - Patent 6630215 The coordination polymerization catalyst to be used, may be a soluble Zieglar-Natta catalyst or a transition metal compound catalyst activated by methyl aluminoxane or a boron compound (so-called metallocene catalyst or half metallocene catalyst, or CGCT catalyst). The polymerization temperature for the aromatic vinyl compound/.alpha.-olefin copolymer using a transition metal compound as a catalyst, is properly from -78.degree. However, a method of copolymerizing an aromatic vinyl compound and an.alpha.-olefin in the presence of a coordination polymerization catalyst, is a preferred method for preparation. www.freepatentsonline.com /6630215.html   (8493 words)

Polymerisation Zieglar Natta catalysts work by making temporary bonds between the metal in the compound, quite often Titanium, and the σ bond of the monomers. A research group lead by Zieglar and Natta found that by using a mixed metal compound it was possible to control where the polymerisation takes place leading to isotactic polymers (ones with side chains all in the same plain) rather than the attactic (randomly arranged side chains) that had previously been used When electrophilic addition occurs it first forms a complex with the catalyst and is then substituted for another monomer in exchange for the chlorine part of the catalyst which produces a product with correctly aligned side groups. www.chem.shef.ac.uk /chm131-2003/cha03lew/polymerisation.html   (457 words)

Delta F Application Note No. 108 - UHP Olefins For years, the Zieglar-Natta catalyst has been widely used in the industry as the catalyst of choice. While metallocene has existed as a catalyst since the late 1950’s, it is only recently that it has been used as a co-catalyst with the Z-N catalyst to produce polyolefins with a narrower molecular weight distribution and other improved properties. The new metallocene catalysts are more susceptible than the Z-N catalysts to oxygen. www.delta-f.com /AppNotes/apnote8.htm   (871 words)

Plastics in the Microwave Isotactic PP is formed using a zinc catalyst, which exhibits high yield and high sterospecificity. www.eng.buffalo.edu /Courses/ce435/2001/Plastic_Microwave/MicrowaveReport.htm   (3055 words)

Model of Isotactic Poly(Vinyl Chloride) (fragment) Using a Zieglar—Natta catalyst, it is possible to build a polymer chain stereoselectively, such that either the groups attached to the double bond in the monomer lie all on the same side of the chain (isotactic) or on alternating sides of the chain (syndiotactic). In this fragment, all the chlorine atoms are on the same side of the polymer chain (isotactic). wps.prenhall.com /wps/media/objects/727/744844/isotactic.html   (90 words)

United Soybean Board The experiment took a Zieglar Natta catalyst, which is a mixture of metal alkyl from group I-III and a transition metal salt from group IV-VIII, and combined it with a photoprecursor. However, Ziegler Natta catalysts are not generally used in photopolymerization. Neckers began research in March to see if Ziegler Natta catalysts can be synthesized photochemically. www.unitedsoybean.org /lib_fs_artview.cfm?id=8&type=two   (297 words)

Ziegler-Natta When the catalyst and cocatalyst come together to form the initiating complex, radicals are produced during intermediate steps of the reaction. For a long time, Ziegler-Natta polymerization was the most useful and versatile reaction for producing polymers of a specific desired tacticity. We also know that co-catalysts are involved, and these are usually based on group III metals like aluminum. www.pslc.ws /macrog/ziegler.htm   (1878 words)

Polyethylene - ArtPolitic Encyclopedia of Politics : Information Portal The lack of branching is ensured by the the aid of a Zieglar-Natta catalyst, where the polymer chain actually grows out from the catalyst. The most common household use of LDPE is in plastic bags[?]; the most common household use of HDPE is in containers for milk, liquid laundry detergent[?], etc. HDPE has virtually no branching and thus stronger intermolecular forces and tensile strength. www.artpolitic.org /infopedia/po/Polyethylene.html   (342 words)

NORTH  GUJARAT  UNIVERCITY (b) Adipic ester synthesis (3) Polymerization, oligomerization and metathesis of alkenes and alkynes : (a) Zieglar - Natta polymerization of ethane (b) Oligometization of butadiene (c) Alkene and alkyne metathesis. Industrial catalyst - preparation, properties, poisioning of catalyst, promoters and inhibitors. Classification of reactors - batch reactors, semi-batch reactors, CFSTER tubular reactors, reactors in series and parallel, space time and space velocity, residence time in reactors. www.ngu.ac.in /academic/MSCP1.htm   (3201 words)

Advanced Instruments Inc Application guide Low ppm level O2 contamination of Zieglar-Natta and metallocene catalysts used to initiate and control the polymerization reaction to assure product quality and processing performance of plastics such as polyethylene, polypropylene, polyesters, and other polymers Low ppm level O2 contamination can act as a catalyst of undesirable polymerization during steam cracking hydrocarbon feedstocks (ethane, propane, butane, naptha, natural gas, etc.) to produce olefin feedstocks (ethylene, propylene, butadiene, H2 and others) that are then separated and purified; and, increasing O2 levels indicate an air leak creating a potentially explosive hazard 0-100 ppm O2 Protection of catalyst and regeneration beds www.aii2.com /applicationguide.html   (1013 words)

SAEED AHMADJO Determenation of EPR structure That synthesized with supper high active Ziegler-Natta catalyst. Slurry Polymerization of Ethylene Using Bi-supported Ziegler-Natta Catalyst. 1) Structural Study of Mono and bi-supported Ziegler-Natta Catalysts of MgCl www.iranpolymerinstitute.org /Resume/pssa.htm   (462 words)

Crossfit.com discussion board: Any chemical engineers here? Zieglar-Natta polymerization involves a catalyst, so this would require controlled processing. I don't think this stuff can be just cured. www.crossfit.com /cgi-bin/discus/discus.cgi?pg=next&topic=3499&page=8486   (767 words)

European Polymer Journal. Xinpei Cao, Linxian Feng, Polymerization of ethylene by the Zieglar-Natta catalyst systems - TiCl www.elsevier.com /cdweb/journals/00143057/viewer.htt?viewtype=keywords&rangeselected=16   (727 words)

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