Test MethodComparative study of the dynamic glass transition temperature by DMA and TMDSC

Measurements of the glass transition temperature obtained by dynamic mechanical analysis (DMA) and temperature modulated differential scanning calorimetry (TMDSC) are reported to be different. This was mainly attributed to the frequency effect. To obtain comparable measurements, experimental conditions were studied. Although some experimental issues had to be fixed, it was possible to apply the same frequency and temperature using quasi-isothermal conditions in both instruments. The method was tested with three different polymer samples. It was then found that when choosing a suitable response parameter, i.e. the phase angle, the dynamic glass transition temperature values obtained by both methods are practically the same.