Polymerization catalyst system utilizing external donor systems and processes of forming polymers therewith

摘要

External donor systems, catalyst systems and olefin polymerization processes are described herein. The external donor systems generally include a first external donor represented by the general formula SiR²_m(OR³)_4-m, wherein each R² is independently selected from alkyls, cycloalkyls, aryls and vinyls, each R³ is independently selected from alkyls and m is from 0 to 4. The external donor systems further include a second external donor represented by the general formula SiR⁴_m(OR⁵)_4-m, wherein each R⁴ is independently selected from alkyls, cycloalkyls, aryls and vinyls, each R⁵ is independently selected from alkyls, m is from 0 to 4 and at least one R⁴ is a C₃ or greater alkyl.