Tacticity

Part of speech: noun

Definitions

1. The arrangement of polymer chain units in a regular, repeating pattern along the molecular backbone that affects material properties; the spatial stereochemistry concerning the orientation of repeating units in a polymer sequence; a measure of the orderly sequence of stereochemical configurations within a synthetic polymer
2. The specific order and spatial arrangement of monomer units in a polymer that determines its stereoregularity and influences physical characteristics; the molecular configuration pattern of polymer chains; the extent to which repeating polymer segments are aligned stereochemically in a consistent manner
3. The organization of chemical units in a polymer into a consistent stereochemical pattern that governs the polymer's crystallinity and mechanical attributes; the spatial sequence pattern of repeated units along the macromolecule; the degree of stereochemical regularity in polymer chains impacting their behavior and structure

Etymology: From the ancient Greek "taktikos," meaning "fit for arranging," which comes from "tassein," "to arrange." English took the root through the sense of ordering things in a system, as in military tactics, and chemists later borrowed it for the orderly placement of atoms. In a polymer, long chains of repeating units carry side groups hanging off the backbone. Tacticity describes how those side groups are oriented relative to one another along the chain: all on the same side, alternating in turn, or scattered with no pattern. The arrangement strongly affects physical properties such as crystallinity, melting point and stiffness, so the same chemical ingredients can produce very different plastics.

Synonyms: arrangement, structure, configuration, pattern, organization

Antonyms: randomness, disorder, chaos, irregularity, anarchy