Dynamic Mechanical Analysis (DMA): characterize the viscoelastic properties of your materials
Dynamic mechanical analysis (DMA) or dynamic mechanical spectroscopy is a method of thermal and mechanical characterization. It measures the viscoelastic behavior of materials as a function of temperature, time, or frequency. It is particularly suitable for the study of polymers, elastomers, composites, and technical materials in sectors such as packaging, automotive, plastics, cosmetics, and medical.
What is Dynamic Mechanical Analysis (DMA)?
DMA (Dynamic Mechanical Analysis) is a technique for measuring the mechanical properties of a material subjected to controlled oscillatory deformation . It allows the determination of the rigidity , energy dissipation and glass transition (Tg) of a material, through the measurement of its storage modulus (E') , loss modulus (E'') and loss factor (tan δ) .
The behavior of polymer materials is often viscoelastic : they exhibit both elastic (energy storage) and viscous (energy dissipation) properties. DMA makes it possible to isolate and quantify these two components as a function of temperature or excitation frequency.
How dynamic mechanical analysis works
The analysis is carried out by applying a sinusoidal force to a sample and measuring its mechanical response. The deformation is recorded as a function of time, which allows the calculation of:
- Storage modulus (E') : reflects the elastic stiffness
- Loss modulus (E'') : indicates the capacity to dissipate energy (viscous behavior)
- Loss factor (tan δ = E''/E') : characterizes the damping and the glass transition
The stress modes are adapted to the shape of the sample and the nature of the material:
- 3-point bending , tension , compression , shear , torsion
Tests can be performed using temperature scanning (typically from -150°C to +500°C), frequency variation, or isothermal monitoring.
Technical characteristics of the DMA
- Highly sensitive measurement of thermal transitions (Tg, Tm, hardening)
- Controlled temperature : from cryogenic to high temperature depending on the instruments
- Analysis frequencies : typically 0.01 Hz to 100 Hz
- Multi-parameter tests : temperature, frequency, humidity
- Types of deformation : bending, tension, compression, shear
- Applicable standards : ISO 6721, ASTM D4065, ASTM D5023, ISO 11359, ICH Q2(R1)
For which matrices?
DMA is particularly suitable for polymer materials and any material exhibiting viscoelastic behavior:
Main industrial applications
Dynamic mechanical analysis is a reference tool in quality control , formulation , materials qualification and R&D , particularly in the following sectors:
Léa Géréec
Technical and scientific advisor
