Ziegler–Natta Catalysts

Abstract First invented in 1953, Ziegler–Natta catalysts have been used widely in the industrial production of polyolefins and other important polymers since the 1960s. In recent years, polymers synthesized with these catalysts account for more than 30% of the total production of polymers. This article briefly introduces the history and main developments of Ziegler–Natta catalysts and explains their preparation, composition, and mechanism of the catalysis process. Particular emphasis is put on the currently more important MgCl 2 ‐supported Ziegler–Natta catalysts. Main features of the olefin polymerization with MgCl 2 ‐supported Ziegler–Natta catalysts are presented, including the formation and structure of active sites, main reactions with the active sites, origin of stereospecificity, reaction kinetics, and morphology of the nascent polymer particles. The main olefin polymerization processes with these catalysts are also briefly discussed.