The Multifaceted Role of Methylaluminoxane in Metallocene-Based Olefin Polymerization Catalysis.

ABSTRACT: In single-site olefin polymerization catalysis, a large excess of cocatalyst is often required for the generation of highly active catalysts, but the reason for this is unclear. In this work, fundamental insight into the multifaceted role of cocatalyst methylaluminoxane (MAO) in the activation, deactivation, and stabilization of group 4 metallocenes in the immobilized single-site olefin polymerization catalyst was gained. Employing probe molecule FT-IR spectroscopy, it was found that weak Lewis acid sites, inherent to the silica-supported MAO cocatalyst, are the main responsible species for the genesis of active metallocenes for olefin polymerization. These weak Lewis acid sites are the origin of AlMe2+ groups. Deactivation of metallocenes is caused by the presence of silanol groups on the

SUBMITTER: Velthoen MEZ 

PROVIDER: S-EPMC5997399 | biostudies-literature | 2018 Jan

REPOSITORIES: biostudies-literature