Polymerization Zeigler-Natta catalysts

C-H Bond activation, with lanthanides Ethylene polymerization, with lanthanides Zeigler-Natta catalyst, lanthanide Diene polymerization, with lanthanides Olefin polymerization, with lanthanides Butadiene polymerization, with lanthanides Isoprene polymerization, with lanthanides Anionic propagation, at lanthanides Living polymers, at lanthanides Pseudo-living polymers, at lanthanides Reaction orders, diene polymerization Active sites, diene polymerization... 

Amass and Stowell et al. replaced the Zeigler-Natta catalyst with a methathesis catalyst for the copolymerization of acetylene with various flexible components including cyclic alkene. The metathesis catalyst has a slower polymerization rate for acetylene and therefore better control of the acetylene segment length. In a series of three papers [67-69], the efficiency of the... 

Most of the early attempts to probe the structures of the active sites of Zeigler-Natta catalysts were based on indirect evidences. Cp TiCl in combination with A1(CH3)3 was shown to be a low-activity polymerization catalyst. Reaction 6.4.1, with characterization of the products, was reported in the mid-1970s (see Section 2.1.5). 

The Unipol process is noted for its ease and flexibility of operations. Here heterogeneous MgCl -supported Ti catalysts are used for the manufacture of LLDPE or PP in fluidized bed reactor. The solid catalyst in an inert liquid medium is fluidized and reacted with the gaseous reactants. In PP manufacturing the use of liquid propylene as a reaction medium is also well-established. The polymerization is carried out in loop reactors using morphology-controlled Zeigler-Natta catalysts. 

The polymerization of ethylene via the Zeigler-Natta process is extremely important commericially and serves as an excellent example of the role of the a-v rearrangement in catalysis (14). The catalyst in this... 

Volume 15 deals with those polymerization processes which do not involve free radicals as intermediates. Chapters 1 and 2 cover homogeneous anionic and cationic polymerization, respectively, and Chapter 3 polymerizations initiated by Zeigler-Natta and related organometallic catalysts. Chapters 4, 5 and 6 deal with the polymerization of cyclic ethers and sulphides, of aldehydes and of lactams, respectively. Finally, in Chapter 7 polycondensation reactions, and in Chapter 8 the polymerization of AT-carboxy-a-amino acid anhydrides, are discussed. 

What could be a possible strategy for investigating the active sites and imparting single-site characteristics to a heterogeneous Zeigler-Natta-type polymerization catalyst How could the oxidation states of the active sites... 

Natta, a consultant for the Montecatini company of Milan, Italy, applied the Zeigler catalysts to other vinyl monomers such as propylene and found that the polymers were of higher density, higher melting, and more linear than those produced by the then classical techniques such as free-radical-initiated polymerization. Ziegler and Natta shared the Nobel Prize in 1963 for their efforts in the production of vinyl polymers using what we know today as solid state stereoregulating catalysts. 

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