Dynamic Mechanical Analysis (DMA): Characterize the viscoelastic properties of your materials
Dynamic mechanical analysis (DMA) , or dynamic mechanical spectroscopy, is a method for thermal and mechanical characterization. It allows for the measurement of the viscoelastic behavior of materials as a function of temperature, time, or frequency. It is particularly well-suited to 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)?
Dynamic Mechanical Analysis (DMA) is a technique for measuring the mechanical properties of a material subjected to controlled oscillatory deformation . It allows the determination of the stiffness , 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 allows these two components to be isolated and quantified as a function of temperature or excitation frequency.
Functioning of dynamic mechanical analysis
The analysis is performed by applying a sinusoidal force to a sample and measuring its mechanical response. The deformation is recorded as a function of time, allowing the calculation of:
- Storage module (E') : reflects elastic stiffness
- Loss modulus (E'') : indicates the ability to dissipate energy (viscous behavior)
- Loss factor (tan δ = E''/E') : characterizes the damping and the glass transition
The methods of stress testing are adapted to the shape of the sample and the nature of the material:
- 3-point bending , tension , compression , shear , torsion
The tests can be carried out by temperature sweep (typically from -150 °C to +500 °C), by frequency variation, or by isothermal tracking.
Technical specifications of the DMA
- Highly sensitive measurement of thermal transitions (Tg, Tm, hardening)
- Temperature controlled : from cryogenic to high temperature depending on the instruments
- Analysis frequencies : typically from 0.01 Hz to 100 Hz
- Multi-parameter testing : 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 suited to 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 expert
