Development of Single-Site New Olefin Polymerization Catalyst Systems Using MgCl2-Based Activators: MAO-Free MgCl2-Supported FI Catalyst Systems

Abstract

Abstract MAO-free new single-site catalyst systems have been developed for olefin polymerization, which are comprised of bis(phenoxy-imine) Ti, Zr, or V complexes (Ti–, Zr–, or V–FI Catalysts) and MgCl2-based compounds. These new catalyst combinations are highly active single-site (Ti–FI Catalysts), exceptionally active (Zr–FI Catalysts), or highly active, thermally robust, single-site (V–FI Catalyst) catalysts for ethylene polymerization. The catalysts can display higher catalytic performance (i.e., catalytic activity, stereoselectivity, thermal stability) than those activated by the well-established MAO activators. In addition, these catalysts are supported, and thus possess a technological advantage vis-à-vis control over polymer morphology, which is essential for commercial application. Therefore, the application of MgCl2-based compounds capable of working both as an activator and a support for non-metallocene complexes provides a conceptually new strategy for the development of high-performance supported single-site catalysts.