Title: secondary relaxation temperature
Long Title: IUPAC Gold Book - secondary relaxation temperature
DOI: 10.1351/goldbook.12800
Status: current

Definition
Temperature characterising a secondary relaxation peak identified as the temperature at which the loss modulus (or loss tangent), measured by DMA or DETA, exhibits a maximum at the measurement frequency, due to the occurrence of localised motions involving only short segments of the polymer chains, or side groups of the polymer chains.

Related Terms
- loss modulus: https://goldbook.iupac.org//terms/view/12782
- loss tangent: https://goldbook.iupac.org//terms/view/12783

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/12800/html
- json: https://goldbook.iupac.org/terms/view/12800/json
- xml: https://goldbook.iupac.org/terms/view/12800/xml

Citation: Citation: 'secondary relaxation 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.12800
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Accessed: 2026-06-04T09:56:03+00:00