12816 IUPAC Gold Book - Vicat softening temperature 10.1351/goldbook.12816 12816 current synonyms: softening point, Vicat hardness, Vicat softening point 1 Temperature at which a thermoplastic polymer reaches a specific degree of softness as measured by a standard test. Usually this temperature is determined using standardised methods, such as indentation tests, or the ring-ball method that characterise the dimensional stability of a polymer to heating. These standardised methods are often polymer specific. For an amorphous polymer, the softening temperature is close to the glass-transition temperature, and for a crystalline polymer the softening temperature is close to but lower than the melting temperature. melting temperature https://goldbook.iupac.org//terms/view/12788 PAC, 2013, 85, 1017. 'Glossary of terms relating to thermal and thermomechanical properties of polymers (IUPAC Recommendations 2013)' on page 1043 (https://doi.org/10.1351/PAC-REC-12-03-02) https://goldbook.iupac.org/terms/view/12816/html https://goldbook.iupac.org/terms/view/12816/json https://goldbook.iupac.org/terms/view/12816/plain Citation: 'Vicat softening temperature' 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.12816 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. 2026-07-13T10:28:32+00:00