isotaktikë
Isotaktikë, also spelled isotacticity, is a term used in polymer chemistry to describe the regularity of monomer units in a polymer chain. It refers to the arrangement of monomer units along the polymer backbone, specifically whether the monomer units are arranged in a regular or irregular pattern. Isotactic polymers have all the side groups on one side of the polymer backbone, syndiotactic polymers have the side groups alternating on either side, and atactic polymers have the side groups randomly distributed. The isotacticity of a polymer can significantly affect its physical properties, such as melting point, solubility, and mechanical strength. For example, isotactic polypropylene is stronger and more crystalline than atactic polypropylene. The isotacticity of a polymer is typically determined using techniques such as nuclear magnetic resonance (NMR) spectroscopy or infrared (IR) spectroscopy.