Alpha-olefin polymerization catalysts

Patent Pending A Ziegler–Natta catalyst, named after Karl Ziegler and Giulio Natta, is a catalyst used in the synthesis of polymers of 1-alkenes (α-olefins). Two broad classes of Ziegler–Natta catalysts are employed, distinguished by their solubility: Heterogeneous supported catalysts based on titanium compounds are used in polymerization reactions in combination with cocatalysts, organoaluminum compounds such as triethylaluminium, Al(C2H5)3. This class of catalyst dominates the industry. Homogeneous catalysts usually based on complexes of Ti, Zr or Hf. They are usually used in combination with a different organoaluminum cocatalyst, methylaluminoxane (or methylalumoxane, MAO). These catalysts traditionally include metallocenes but also feature multidentate oxygen- and nitrogen-based ligands.