Tandem catalysis of iron and titanium non-metallocene catalysts for the production of branched polyethylene
•A novel binary tandem catalyst system composed of two non-metallocene catalysts•2,6-Bis(imino)pyridyl iron complex (1) and mono β-diiminato titanium complex (2)•In-situ copolymerize ethylene to branched polyethylene with high activity•Polymers with various branches and branching degrees can be efficiently produced.
Branched polyethylene was successfully produced with ethylene as the sole monomer stock by a novel binary tandem catalyst system composed of 2,6-bis(imino)pyridyl iron complex (1) and mono β-diiminato titanium complex (2) activated only by MMAO, in which the complex 2 was the first non-metallocene titanium complex used as copolymerization catalyst. The copolymerization activity can reach up to 106 g/mol Ti·h·atm. And by simple adjustment of the catalyst molar ratios and polymerization conditions, polymers with various branches including ethyl, butyl and long branches and varying branching degrees (from 0 to 10.7/1000 C) can be efficiently produced.
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Journal: Catalysis Communications - Volume 45, 5 February 2014, Pages 7–10