Coordineerimispolümerisatsioon

Coordineerimispolümerisatsioon, also known as coordination polymerization or Ziegler-Natta polymerization, is a method for synthesizing polymers where a transition metal catalyst plays a crucial role. Unlike ionic or free-radical polymerization, this process involves the monomer coordinating to the active metal center of the catalyst before being incorporated into the growing polymer chain. This coordination step is key to controlling the stereochemistry of the polymer, leading to highly regular structures, particularly in the case of polyolefins like polyethylene and polypropylene.

The mechanism typically involves the formation of a catalyst-monomer complex followed by migratory insertion of the monomer into the metal-carbon bond of the growing chain. The nature of the catalyst, including the specific transition metal and its ligands, as well as the reaction conditions, significantly influences the rate of polymerization, molecular weight, and tacticity of the resulting polymer. Ziegler-Natta catalysts, famously developed by Karl Ziegler and Giulio Natta, revolutionized the plastics industry by enabling the production of stereoregular polymers with improved mechanical properties. Other important coordination polymerization catalysts include metallocenes, which offer even greater control over polymer architecture. This method is widely used for producing materials with specific properties for various applications.