- Dimerization method for high activity and selectivity propylene
-
The invention provides a dimerization method for high activity and selectivity propylene. The method includes the following steps that methylaluminoxane (MAO) or modified methylaluminoxane (MMAO) is used as a catalyst promoter, and the propylene is subjected to a dimerization reaction under the catalytic action of an ethylidene bridged substituted diindene titanium group metal complex catalyst; and the ethylidene bridged substituted diindene titanium group metal complex catalyst is an internal compensation (meso-) ethylidene bridged substituted diindene titanium group metal complex catalyst or a racemization (rac-) ethylidene bridged substituted diindene titanium group metal complex catalyst. Compared with the prior art, the dimerization method provided by the invention is high in catalytic activity and high in dimerization selectivity, the rate can reach 99%, numerous follow-up operation steps in separation of products with the high degree of polymerization are omitted, the industrialization cost is reduced, and the industrial production needs can be met.
- -
-
Paragraph 0058; 0059; 0060; 0061; 0062; 0063
(2017/06/02)
-
- Control of stereoerror formation with high-activity "dual-side" zirconocene catalysts: A novel strategy to design the properties of thermoplastic elastic polypropenes
-
The new C1-symmetric complexes rac-[1-(9-η5-fluorenyl)-2-(2-methylbenz[e]-1-η 5-indenyl)ethane]-zirconium dichloride (14a), rac-[1-(9-η5-fluorenyl)-2-(4,5-cyclohexa-2-methyl-1-η 5-indenyl)ethane]zirconium dichloride (14b), and rac-[1-(9-η5-fluorenyl)-2-(5,6-cyclopenta-2-methyl-l-η 5-indenyl)ethane]zirconium dichloride (15) were prepared in up to 93% yield. These compounds, activated with methyl aluminoxane, exhibit high active propene polymerization rates which remain constant over hours, even at elevated polymerization temperatures of 50 and 70°C. The two different coordination sites of these "dual-side" catalysts lead to isotactic polypropenes with variable amounts of stereoerrors, depending on the monomer concentration. The 2-methyl substituent of the indenyl ligands results, at the same time, in significantly increased molecular weights of the polymer products (up to 2.3 × 105 g mol-1), the bulk properties of which can be adjusted from flexible, semicrystalline thermoplastic to excellent thermoplastic elastic.
- Dietrich, Ulf,Hackmann, Martijn,Rieger, Bernhard,Klinga, Martti,Leskelae, Markku
-
p. 4348 - 4355
(2007/10/03)
-