Dynamic Thermo-mechanical Analysis (DMA)
Dynamic Mechanical Analysis (DMA) is an important tool for figuring out the viscoelastic properties of materials, especially polymers. A method for measuring the change in stress or strain when the stress or strain is the same and stays the same over time. DMA is an important method for measuring the mechanical and viscoelastic properties of materials like thermoplastics, thermosets, elastomers, ceramics, and metals. In DMA, the sample is stressed periodically in one of several different ways.
Working:
The sample is clamped in the DMA instrument’s measuring head. During measurement, the probe puts a sinusoidal force on the sample. The change in shape caused by the sinusoidal force is measured, and the relationship between the change in shape and the force applied is calculated. The applied stress and strain as a function of temperature or time can be used to figure out properties like elasticity and viscosity. DMA is used to measure how different types of polymer materials deform in different ways. There are tension, compression, dual cantilever bending, three-point bending, and shear modes. The best model should be chosen based on the shape of the sample, its modulus, and the reason for measuring it.
Advantages of DMA:
- Dynamic mechanical analysis is one of the most important ways to figure out how viscoelastic polymers are.
- DMA is different from many similar methods because it can tell you about both major and minor changes in materials.
- It is also more sensitive to changes in polymers after their glass transition temperature.
- This method can quickly scan and calculate the modulus for a range of temperatures because it uses oscillating stress.
- It is the only method that can both figure out the basic structure of a polymer system and give information about how the modulus changes with temperature.
