Title: secondary relaxation peak
Long Title: IUPAC Gold Book - secondary relaxation peak
DOI: 10.1351/goldbook.12799
Status: current

Definition
Any peak in a loss curve either at a lower temperature than the temperature of the alpha relaxation peak or at a higher frequency than the frequency of the alpha relaxation peak.

Note
The use of the term "secondary relaxation transition peak" is discouraged.

Related Terms
- alpha relaxation peak: https://goldbook.iupac.org//terms/view/12741
- beta relaxation peak: https://goldbook.iupac.org//terms/view/12745
- gamma relaxation peak: https://goldbook.iupac.org//terms/view/12772
- loss curve: https://goldbook.iupac.org//terms/view/12781

Source
- PAC, 2013, 85, 1017. 'Glossary of terms relating to thermal and thermomechanical properties of polymers (IUPAC Recommendations 2013)' on page 1038 (https://doi.org/10.1351/PAC-REC-12-03-02)

Other Outputs
- html: https://goldbook.iupac.org/terms/view/12799/html
- json: https://goldbook.iupac.org/terms/view/12799/json
- xml: https://goldbook.iupac.org/terms/view/12799/xml

Citation: Citation: 'secondary relaxation peak' 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.12799
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: 2026-06-04T10:47:02+00:00