Dynamic mechanical analysis
![Figure 1. A typical DMA tester with grips to hold sample and environmental chamber to provide different temperature conditions. A sample is mounted on the grips and the environmental chamber can slide over to enclose the sample.](/Images/godic/202501/10/Dynamic+Tests+Setup+Chem+5381452.jpg")
![Figure 2. A temperature sweep test on Polycarbonate. Storage Modulus (E’) and Loss Modulus (E’’) against temperature were plotted. Different initial static load and strain were used. The glass transition temperature of Polycarbonate was detected to be around 150 degree C.The Polycarbonate samples were made from the material purchased from Mcmaster-Carr, #8574k26](/Images/godic/202501/10/Temp_Sweep_Chem5381452.jpg")
![Figure 3. General schematic of a DMA instrument.](/Images/godic/202501/10/Schematic_of_DMA1452.png")
![Figure 4. Torsional versus Axial Motions.](/Images/godic/202501/10/Analyzers1452.png")
Dynamic mechanical analysis (abbreviated DMA, also known as dynamic mechanical spectroscopy) is a technique used to study and characterize materials. It is most useful for studying the viscoelastic behavior of polymers. A sinusoidal stress is applied and the strain in the material is measured, allowing one to determine the complex modulus. The temperature of the sample or the frequency of the stress are often varied, leading to variations in the complex modulus; this approach can be used to locate the glass transition temperature of the material, as well as to identify transitions corresponding to other molecular motions.