Single-site catalysis

Exxpol [Exxon polymerization] A gas-phase process for making polyethylene from ethylene. The process uses single-site catalysis (SSC), based on a zirconium metallocene catalyst. Developed by Exxon Chemical Company in 1990 with plans to be commercialized in 1994. 

Single Site Catalysis on Oxides and Metals Prepared via Surface Organometallic Chemistry... 

Catalysis by design (e.g., single-site catalysis for polyolefin polymerization)... 

Application Metocene polypropylene (PP) technology upgrades existing and newly built PP plants by extending plant capability to cover specialty PP products with specific and unique features that can be produced with single-site catalysis, in addition to the existing conventional product portfolio. 

Breakthroughs in single-site catalysis have completely transformed our view of alpha-olefin polymerization catalysis. The conventional Ziegler—Natta catalysts used in industrial production of polyolefins... 

AA Montagna, RM Burkhardt, AH Dekmezian. Single site catalysis its evolution and impact on the polymer field. Proceedings of Metallocene Technology 97 Conference. Chicago, 1997, pp 1-9. 

H. R. Blum, in MetCon 2000, Polymers in Transition Platforms in Single-Site Catalysis , Houston, Tex., 2000. 

The dominant position of Ziegler-Natta catalysts in the manufacture of polyolefins, in particnlar PP, is likely to continue for a considerable length of time, despite the many developments taking place in the field of metallocene and other single-site catalysis. Indeed, the range of polymer types and grades is so varied... 

A.A. Montagna, and J.C. Floyd, Single-sited catalysis leads next polyolefin generation, Hydrocarbon Processing, p. 57-62, March 1994. 

We can employ coordination polymerization to produce stereoregular polystyrene. By performing this type of reaction at low temperatures, using Ziegler-Natta or single-site catalysis, we can prepare isotactic and syndiotactic versions of polystyrene. 

One clear illustration of the importance of this issue is the recent reports of improved adhesion to polyolefins produced by single-site catalytic polymerization of ethylene and propylene. Single-site catalysis yields materials of a narrower molecular weight distribution. Reports of these materials suggest that the reduced content of species below the entanglement molecular weight is responsible for their enhanced adhesion (9). 

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