Supported Metallocene Catalysts

Since the discovery of metallocene catalysts for olefin polymerization in the 1950s and the foundation laying of the catalysts by Kaminsky et al. in the 1980s, they have been at the forefront of the research in the field of chemical catalysis and polymer materials in the international arena, and the catalytic system usually consists of metallocene compounds, co-catalysts (MAO, MMAO), and silica carriers, and the catalytic polymerization mechanism is that the metallocene metal interacts with the co-catalysts to form a cationic The mechanism of catalytic polymerization is that metallocene interacts with co-catalysts to form cationic catalytic activity centers, thus producing polymers with uniform molecular weight, structure and composition in the catalytic olefin polymerization. Another important feature of metallocene catalysts is that various parameters of polymers, such as molecular weight, molecular weight distribution, polymer regularity, copolymerization monomer content and distribution, can be controlled by changing the structure of metallocene catalysts. The use of different metallocene catalysts can not only obtain all kinds of traditional polyolefins with superior performance, but also synthesize some new materials that cannot be prepared by traditional Ziegler-Natta olefin polymerization catalysts.

Comparison with conventional Ziegler-Natta catalyst:

(1) very high catalytic activity; 

 (2) With a single active center, it is capable of precisely controlling the relative molecular mass of the polymer, molecular weight distribution, copolymerization monomer content and its distribution on the main chain and crystalline structure;

(3) It has excellent catalytic copolymerization ability, which can almost make most of the copolymerized monomers copolymerize with ethylene, and many new polyolefin materials can be obtained, such as α-olefin monomer polymerization, metallocene polyethylene (mPE), and so on.

The following catalyst systems are available: 1. mPE catalyst; 2. mPP catalyst; 3. POE CGC catalyst. 

Process flow for supported metallocene catalyst