ASTM E1640-23 PDF

Full title and description

ASTM E1640-23 — Standard Test Method for Assignment of the Glass Transition Temperature by Dynamic Mechanical Analysis. This test method defines procedures and conventions for locating the glass transition region and assigning a single glass transition temperature (Tg) for amorphous, semi-crystalline and thermally stable polymeric materials using dynamic mechanical analyzers (DMA).

Abstract

ASTM E1640-23 specifies how to use dynamic mechanical analysis to detect the glass transition of materials by monitoring changes in viscoelastic properties (storage modulus, loss modulus, and tan delta) as a function of temperature and frequency. The standard identifies the recommended method for assigning a single Tg (commonly from the extrapolated onset of the storage-modulus decrease, with alternative approaches such as loss-modulus maximum or tan delta peak noted), instrumentation considerations, typical temperature and modulus ranges, and intended applications in research, development and quality control.

General information

• Status: Published / Active
• Publication date: August 1, 2023 (designation E1640-23)
• Publisher: ASTM International
• ICS / categories: ICS 81.040.10 (Raw materials and raw glass) — thermal analysis / materials characterization category
• Edition / version: E1640-23 (current edition; supersedes E1640-18)
• Number of pages: 7

Scope

This test method covers assignment of a glass transition temperature (Tg) using dynamic mechanical analyzers. It is applicable to thermoplastic polymers, thermoset polymers, and partially crystalline materials that remain thermally stable in the glass transition region. The method is intended for specimens with elastic moduli roughly in the range 0.5 MPa to 100 GPa and for temperature ranges determined by the instrumentation (to encompass most materials the minimum recommended temperature extends to about −150 °C). Values are given in SI units.

Key topics and requirements

• Principle: measure viscoelastic response (storage modulus, loss modulus, tan δ) while the specimen is oscillated and temperature is changed.
• Assignment of Tg: recommended primary designation is the extrapolated onset of the decrease in storage modulus; alternate indicators (loss-modulus peak, tan δ peak) are described and acknowledged to give method-dependent Tg values.
• Specimen geometry and preparation: use specimens of known geometry consistent with instrument requirements and the selected test mode (tension, bending, shear); follow instrument manufacturer guidance for clamping and strain levels.
• Frequency and heating rate: test frequency and heating rate affect measured transitions; standard describes reporting requirements so results can be compared (frequency, amplitude/strain, heating rate, atmosphere).
• Applicable material/modulus range: intended for materials with elastic modulus approximately 0.5 MPa to 100 GPa.
• Temperature range and instrumentation limits: method depends on DMA capabilities; typical lower bound recommended to around −150 °C to allow coverage of many polymer systems.
• Use cases: quality control, specification acceptance, research and development, monitoring cure and thermal history effects.
• Reporting: requires clear reporting of the chosen Tg definition, test frequency, heating rate, specimen description, atmosphere, and instrument settings to ensure reproducibility and comparability.

Typical use and users

Common users include materials scientists, polymer engineers, testing laboratories, quality-control departments, R&D groups, instrument manufacturers, and regulatory or certification bodies. Typical uses are Tg characterization for specification and acceptance testing, formulation and process development, cure monitoring of thermosets, comparison of materials, and failure analysis where thermal-mechanical behavior is relevant.

Related standards

Standards commonly used alongside or as complementary methods include ASTM E1356 (DSC-based assignment of Tg), ASTM E1545 / E1545-xx (thermomechanical analysis for Tg), ASTM E1824 (TMA tension method), ASTM E2602 (modulated-temperature DSC methods), and other ASTM thermal-analysis and instrument-calibration standards (for example E1867, E1363, E2918). The current edition E1640-23 supersedes E1640-18.

Keywords

glass transition, Tg, dynamic mechanical analysis, DMA, storage modulus, loss modulus, tan delta, viscoelasticity, thermal analysis, polymers, thermoplastics, thermosets, semi-crystalline materials

FAQ

Q: What is this standard?

A: ASTM E1640-23 is a test method that defines how to assign a glass transition temperature (Tg) using dynamic mechanical analysis (DMA).

Q: What does it cover?

A: It covers procedures, preferred Tg assignment conventions (for example onset of storage-modulus decrease), instrumentation and reporting requirements, applicable temperature and modulus ranges, and recommended practice for obtaining reproducible DMA-based Tg values for polymeric materials.

Q: Who typically uses it?

A: Materials and polymer scientists, QA/QC labs, R&D teams, instrument vendors, and testing laboratories use E1640 to characterize thermal-mechanical transitions and to support specification, acceptance, and research work.

Q: Is it current or superseded?

A: The current edition is E1640-23, approved August 1, 2023. It supersedes the previous edition E1640-18.

Q: Is it part of a series?

A: E1640-23 is part of a family of ASTM thermal-analysis standards maintained by Committee E37 (Thermal Measurements). It is commonly used with other Tg-assignment standards (for example DSC and TMA methods) and with instrument calibration and validation standards from the same committee.

Q: What are the key keywords?

A: glass transition, Tg, dynamic mechanical analysis, storage modulus, loss modulus, tan delta, viscoelastic, polymers, thermal analysis.