12209 IUPAC Gold Book - chain stiffness 10.1351/goldbook.12209 12209 current 1 Parameter describing the end-to-end distance of a linear, single-strand macromolecular chain having unperturbed dimensions relative to that of a model macromolecular chain not subject to short-range interactions. The steric factor, \(\sigma\), Kuhn segment length, \(l^{\prime}\), and persistence length, \(a\), are all measures of chain stiffness. Kuhn segment length https://goldbook.iupac.org//terms/view/12205 PAC, 2015, 87, 71. 'Definitions of terms relating to individual macromolecules, macromolecular assemblies, polymer solutions, and amorphous bulk polymers (IUPAC Recommendations 2014)' on page 80 (https://doi.org/10.1515/pac-2013-0201) https://goldbook.iupac.org/terms/view/12209/html https://goldbook.iupac.org/terms/view/12209/json https://goldbook.iupac.org/terms/view/12209/plain Citation: 'chain stiffness' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.12209 The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) for individual terms. If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org . The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using. 2026-07-14T06:50:40+00:00