15381 IUPAC Gold Book - azeotropic copolymerisation 10.1351/goldbook.15381 15381 current 1 Binary copolymerization in which the two monomer reactivity ratios, \(r_{12}\) and \(r_{21}\) are not both equal to unity yet the copolymerization forms a copolymer with its molar ratio of monomer units equal to the molar ratio of monomers in the monomer feed. An azeotropic polymerization occurs at only one specific molar ratio of monomers in the feed. Although, in its equality of copolymer and monomer-feed compositions, an azeotropic polymerization has the same feature as an ideal binary copolymerization in which \(r_{12} = r_{21} = 1\), it is not an ideal copolymerization as it has \(r_{12} r_{21} \neq 1\). Binary copolymerization https://goldbook.iupac.org//terms/view/15383 ideal binary copolymerization https://goldbook.iupac.org//terms/view/15405 ideal copolymerization https://goldbook.iupac.org//terms/view/15406 monomer reactivity ratios https://goldbook.iupac.org//terms/view/15410 PAC, 2008, 80, 2163. 'Glossary of terms related to kinetics, thermodynamics, and mechanisms of polymerization (IUPAC Recommendations 2008)' on page 2166 (https://doi.org/10.1351/pac200880102163) https://goldbook.iupac.org/terms/view/15381/html https://goldbook.iupac.org/terms/view/15381/json https://goldbook.iupac.org/terms/view/15381/plain Citation: 'azeotropic copolymerisation' 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.15381 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. 2026-04-18T05:13:35+00:00