ZieglerNatta

Ziegler–Natta catalysts are a family of organometallic catalysts used for the polymerization of alpha-olefins, most notably ethylene and propylene, to produce polyolefins with controlled tacticity and high molecular weight. They emerged from the work of Karl Ziegler and Giulio Natta in the 1950s and 1960s. A typical heterogeneous Ziegler–Natta system consists of a titanium halide, such as titanium tetrachloride, supported on a magnesium chloride carrier, activated with an organoaluminum co-catalyst (for example triethylaluminum). Under appropriate conditions, these catalysts enable stereoregular polymerization, allowing the production of isotactic polypropylene, which has crystalline structure and useful mechanical properties.

Over the years, Ziegler–Natta catalysts transformed the polymer industry by enabling efficient production of polyolefins, including high-density polyethylene and various copolymers. They operate via coordination-insertion polymerization, where the olefin coordinates to a metal center, inserts into a growing polymer chain, and regenerates a catalytic active site.

In addition to the classical heterogeneous systems, homogeneous Ziegler–Natta catalysts were developed, including late-20th-century single-site catalysts such as metallocenes, which offer different activity and microstructure control.

Ziegler and Natta were awarded the Nobel Prize in Chemistry in 1963 for their discoveries in polymerization of long-chain molecules. The term Ziegler–Natta continues to describe both traditional supported catalysts and related homogeneous catalysts used in modern polyolefin production.