Burkhard Eric Wagner

Developments with High-Activity Titanium, Vanadium, and Chromium Catalysts in Ethylene Polymerization

Recent developments with high-activity catalysts based on titanium, vanadium, and chromium -compositions continue to illustrate the unique behavior of each metal center in ethylene polymerization catalysis. Bimetallic complexes containing magnesium-titanium- or magnesiumaluminum-electron donor complexes have been identified and characterized. Interestingly, studies with TiCl3 reveal that complex formation with MgCl2 is not required for obtaining high-activity catalysts.

New Catalysis and Process for Ethylene Polymerization

Olefin polymerization catalysis continues to be a fertile area of research with worldwide participation in both industrial and academic laboratories.1–3 While much of this research has centered on methods to increase the productivity of catalysts, there has been and continues to be much active research on other features of olefin polymerization catalysis. The specific composition of the catalyst exerts an important effect on polymer molecular weight and molecular weight distribution (MWD), comonomer incorporation and copolymerization kinetics, and on the degree of stereoregularity. Moreover, the size, shape, and porosity (morphology) of the catalyst particle plays an important role in regulating the morphology of the resultant polymer. Development of low cost, reproducible processes for catalyst manufacture continues to be another important objective in catalyst research.4 The focus of industrial research in olefin polymerization catalysis centers on the chemistry and technology necessary to obtain simultaneously favorable catalyst responses in all of the areas described above.