Improved repeatability of DSC characterization of TPU by means of supportive use of heat-transfer agents

The characterization of materials by means of differential scanning calorimetry (DSC) may contain measurement artefacts originating from the undefined contact area between the material sample and the pan surface. Especially in cases where low thermal conducting materials are investigated, this contact area strongly determines the heat transfer towards the material sample and, thus, the obtained results. As a remedy, the supportive use of heat-transfer agents (HTA) in DSC characterization is proposed in this paper. The beneficial effect of HTA is demonstrated for thermoplastic polyurethane (TPU) with its original DSC data showing significant variation of measurement data, most notably in the temperature range where softening of the material occurs. In the course of an experimental study, covering a temperature range from −40 °C to 270 °C, TPU specimens are analysed with and without HTA considering different heating rates, showing an improved reproducibility of DSC results by the supportive use of HTA, especially in case of higher heating rates.