syndiotaktiseksi

syndiotaktiseksi is the Finnish adjective used to describe a polymer with a syndiotactic arrangement of substituents along its backbone. Tacticity is the stereochemical order of substituents at successive chiral centers; in a syndiotactic polymer, configurations alternate along the chain, in contrast to isotactic polymers (same configuration) and atactic polymers (no regular order). The tacticity affects crystallinity and thermal properties: syndiotactic polymers often crystallize differently from their atactic counterparts and may differ from isotactic forms in melting behavior and mechanical properties, depending on the polymer.

Common examples include syndiotactic polystyrene (sPS) and syndiotactic polypropylene (sPP). These materials can form distinct crystalline forms and are studied for processing and performance in higher-temperature or high-clarity applications. Synthesis is controlled by catalyst and conditions; single-site and metallocene catalysts are used to bias toward syndiotactic sequences, sometimes with specific comonomers.

In Finnish literature, syndiotaktiseksi describes a material’s stereochemical arrangement, crystallinity, and related properties, signaling an alternating, syndiotactic architecture.