Title: g′-factor Long Title: IUPAC Gold Book - g′-factor DOI: 10.1351/goldbook.12213 Status: current Definition Ratio of the intrinsic viscosity of a branched molecule, \([\eta_{\rm{b}}]\), to that of an otherwise identical linear molecule, \([\eta_{\rm{l}}]\), of the same relative molecular mass in the same solvent at the same temperature, i.e., \(g^{\prime} = [\eta_{\rm{b}}]/[\eta_{\rm{l}}]\). Note The \(g^{\prime}\mbox{-}\rm{factor}\) is a quantity characterizing the effects of long-chain branches on the size of a branched molecule. Related Terms - g-factor: https://goldbook.iupac.org//terms/view/12212 - long-chain branches: https://goldbook.iupac.org//terms/view/12211 Source - PAC, 2015, 87, 71. 'Definitions of terms relating to individual macromolecules, macromolecular assemblies, polymer solutions, and amorphous bulk polymers (IUPAC Recommendations 2014)' on page 81 (https://doi.org/10.1515/pac-2013-0201) Other Outputs - html: https://goldbook.iupac.org/terms/view/12213/html - json: https://goldbook.iupac.org/terms/view/12213/json - xml: https://goldbook.iupac.org/terms/view/12213/xml Citation: Citation: 'g′-factor' 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.12213 License: 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. Collection: If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org . Disclaimer: 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. Accessed: 2026-06-13T16:05:01+00:00