Kaminsky-Brintzinger catalyst

Kaminsky-Brintzinger systems, 16 82 Kaminsky catalysts, 17 702 20 426 Kaminsky metallocene catalysts,... 

Scheme 1.28. Polymerization of propylene with Kaminsky-Brintzinger type catalyst.

After Kaminsky, Brintzinger, and Ewen discovered homogeneous metallocene/ methylaluminoxane (MAO) catalysts for stereospecific a-olefin polymerizatiOTi (for reviews on olefin polymerization, see [13-21]), the first report [22, 23] rai addition cycloolefin polymerization without ROMP appeared. This stimulated a great interest in these polymers and in catalysts for cycloolefin polymerization (Fig. 1). Cycloolefins such as cyclopentene, cyclooctene, and norbomene can be polymerized via addition (Fig. 2). Polycycloolefins by metallocenes are difficult to process due to their high melting points and their low solubility in common organic solvents. However, metallocenes allow the synthesis of cyclic olefin copolymers (COC), especially of cyclopentene and norbomene with ethene or propene, which represent a new class of thermoplastic amorphous materials (Scheme 1) [24, 25]. 

Kaminsky W, Noll A (1955) in Fink G, Miilhaupt R, Brintzinger HH (eds) Ziegler Catalysts. Springer Verlag, Berlin, p 149... 

Kaminsky, W. Noll, A. Polymerization of Phenyl-substituted Cyclic Olefins with Metallocene/MAO Catalysts. In Ziegler Catalysts-, Fink, G., Miilhaupt, R., Brintzinger, H.-H., Eds. Springer Berlin, 1995 p 149. 

Molecular weight measurements are far less sensitive to variables which are by their nature most affected by experimental error, such as catalyst amount or catalyst/monomer purity, and, more important, on the number of active centers, but are highly sensitive to the catalyst structure, monomer concentration, and polymerization temperature. Hence, reliable molecular weights can give much information on the nature of the active sites. Studies of this kind have been reported by Miilhaupt and Brintzinger on catalysts C2-T24 and 25, by Kaminsky and Werner on three Ci-symmetric zirconocenes, and... 

In the early 1980s, Kaminsky and Sinn discovered an efficient way to activate homogeneous metallocene catalysts with methylaluminoxane (MAO). Titanocene and zirconocene complexes activated with MAO exhibited very high activity for ethylene polymerization these early systems, however, still had low activity for propylene polymerization and formed atactic polypropylene [5]. Met-allocene/MAO systems containing stereospecific ligands could be used to catalyze the polymerization of prochiral olefins (a-olefins) through the use of catalysts with well-defined active sites [6]. Later, Brintzinger [7] and Ewen... 

Prosenc M-H, Schaper F, Brintzinger H-H (1999) In Kaminsky W (ed) Metalorganic catalysts for synthesis and polymerization. Springer, Berlin, p 223... 

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