GB/T 33061.2-2025Plastics - Determination of dynamic mechanical properties - Part 2: Torsion-pendulum method (English PDF)

Foreword

This document complies with the provisions of GB/T 1.1-2020 "Standardization Work Guidelines Part 1: Structure and Drafting Rules of Standardization Documents".

Drafting.

This document is Part 2 of GB/T 33061 "Determination of Dynamic Mechanical Properties of Plastics". GB/T 33061 has already published the following...

part.

---Part 1: General Rules;

---Part 2: The Torsional Pendulum Method;

---Part 3: Resonance Curve Method under Bending Vibration;

---Part 4: Non-resonant tensile vibration method;

---Part 5: Non-resonant bending vibration method;

---Part 6: Non-resonant shear vibration method;

---Part 7: Non-resonant torsional vibration method;

---Part 10: Determination of Complex Shear Vibration Viscometer Using a Parallel Plate Vibrating Rheometer;

---Part 11: Glass Transition Temperature;

---Part 12: Non-resonant compressive vibration method;

This document is modified to adopt ISO 6721-2:2019 "Determination of dynamic mechanical properties of plastics - Part 2: Torsion pendulum method".

This document has undergone the following structural adjustments compared to ISO 6721-2:2019.

---The symbols in formulas 10.1, 10.2, 10.3, and 10.4 in Chapter 10 correspond to 10.1 in ISO 6721-2:2019;

---Appendix D corresponds to Chapter 11 of ISO 6721-2:2019.

The technical differences between this document and ISO 6721-2:2019, and the reasons therefor, are as follows.

---The normatively referenced GB/T 33061.1 replaces ISO 6721-1 (see Chapters 3, 4, 5.6~5.9, 6.1, 6.3).

Chapters 7-9 and Chapter 12 are included to adapt to my country's technological conditions and increase operability.

---Change "and insert formula (5) to get formula (12)" to "substitute formula (1) into formula (11) to get formula (12)" (see 10.4).

Easy for operators to use.

The following editorial changes have been made to this document.

---ISO 4664-2 has been replaced by GB/T 9870.2 (see Chapter 1) for informational purposes;

---ISO 6721-3 has been replaced by GB/T 33061.3 (see Chapter 1), which is cited in the informational reference.

Please note that some content in this document may involve patents. The issuing organization of this document assumes no responsibility for identifying patents.

This document was proposed by the China Petroleum and Chemical Industry Federation.

This document is under the jurisdiction of the National Technical Committee on Plastics Standardization (SAC/TC15).

Introduction

Dynamic mechanical analysis (DMA) measures the response of a material under alternating stress or strain under programmed temperature control. The results reflect...

Viscoelasticity of materials.

This document uses the DMA method to determine the changes in storage modulus and loss modulus of plastics with temperature under torsion test mode.

The above results can characterize information related to phase transitions (such as glass transitions) and plastic deformation of plastics.

GB/T 33061, "Determination of Dynamic Mechanical Properties of Plastics", specifies the methods for determining the dynamic mechanical properties of rigid plastics within the linear viscoelastic behavior range.

The method for assessing mechanical properties is proposed to consist of the following parts.

---Part 1: General Rules. The purpose is to establish general definitions and related content for test methods for determining dynamic mechanical properties.

---Part 2: Torsional Pendulum Method. The aim is to establish a comparable method for determining the stored energy and loss components of the torsional modulus.

---Part 3: Resonance Curve Method under Bending Vibration. The aim is to determine the flexural composite modulus of homogeneous plastics and the laminations used for sound insulation.

Determining the damping properties of plastics and establishing comparable methods.

---Part 4: Non-resonant tensile vibration method. The purpose is to establish a forced non-resonant method for determining the tensile complex modulus of plastics.

Comparable methods.

---Part 5: Non-resonant bending vibration method. The purpose is to establish a forced non-resonant method for determining the complex bending modulus of plastics.

Comparable methods.

---Part 6: Non-resonant shear vibration method. The aim is to establish a forced non-resonant method for determining the complex shear modulus of plastics.

Comparable methods.

---Part 7: Non-resonant torsional vibration method. The aim is to obtain the torsional non-resonant complex modulus of the shear modulus of strip or rod-shaped solid polymers.

The resonance method was used to determine and establish comparable methods.

---Part 8: Longitudinal Shear Vibration Wave Propagation Method. The aim is to store the longitudinal complex modulus and shear complex modulus of polymers.

Determination of energy components and establishment of comparable methods.

---Part 9: Tensile Vibration Sound Velocity Pulse Propagation Method. The purpose is to determine the stored energy component of the complex tensile modulus of polymers.

The method of comparison.

---Part 10: Determination of Complex Shear Vibration Viscosity Using a Parallel Plate Vibrating Rheometer. The aim is to provide information on the dynamic rheology of polymer melts.

The determination of the test method can establish comparable methods.

---Part 11: Glass Transition Temperature. The purpose is to establish a reliable method for determining the glass transition temperature (Tg) of dynamic mechanical properties.

The method of comparison.

---Part 12: Non-resonant compressive vibration method. The aim is to establish a comparable method for determining the complex compressive modulus of polymers.

Determination of dynamic mechanical properties of plastics Part 2: Torsion Method

1 Scope

This document describes a method for applying linear dynamic mechanical properties of plastics under small strain conditions within a frequency range of 0.1 Hz to 10 Hz.

(Method A and Method B) Determine the changes in storage modulus and loss modulus of plastics with temperature in torsion test mode.

Note. The relationship between storage modulus, loss modulus, and temperature was measured over a sufficiently wide temperature range (-50°C to 150°C) to obtain the correlation of the polymer in the transition state.

Information such as glass transition and melt transition is provided, as well as information about the initial plastic flow.

This document does not apply to asymmetric laminates (see GB/T 33061.3) and rubber (see GB/T 9870.2).

2 Normative references

The contents of the following documents, through normative references within the text, constitute essential provisions of this document. Dated citations are not included.

For references to documents, only the version corresponding to that date applies to this document; for undated references, the latest version (including all amendments) applies.

This document.

GB/T 33061.1 Determination of dynamic mechanical properties of plastics – Part 1: General rules (GB/T 33061.1-2025, ISO 6721-1.

2019, MOD)

3 Terms and Definitions

The terms and definitions defined in GB/T 33061.1 apply to this document.

4 Principles

A sample with a uniform cross-section is clamped by two clamps, one of which is fixed in place, and the other is connected to a disk via a connecting rod.

The disk is an inertial component. The end of the specimen connected to the disk moves with the disk, undergoing freely decaying torsional vibration. The vibration mode is...

In GB/T 33061.1, IV has a modulus type of Gto as defined in GB/T 33061.1.

The inertial component is suspended from the specimen (Method A, Figure 1) or a thin thread (Method B, Figure 2). In the latter case, the thin thread is also an elastic vibrator.

Part of the dynamic system.