Dynamic mechanical analysis (DMA) is a technique that measures the viscoelastic properties of materials, such as polymers, by applying an oscillating force and measuring the response. A DMA thermogram is a plot that shows how the elastic modulus (E), the damping factor (tan δ), and other parameters vary with temperature, frequency, or time. A DMA thermogram can provide information about the transitions, molecular structure, stiffness, and relaxation behavior of the material.
There are many references that can help you with thermogram interpretation, depending on your level of background and interest. Here are some sources that you can check out: