Determination of the PCM melting temperature range using DSC

• The PCM melting temperature range with dynamic DSC method was not accurate.
• A new DSC method was proposed to determine the PCM ending melting temperature.
• The ending melting temperature was independent of the heating rate.

The melting temperature range is one of the most important parameters for phase change material (PCM), it affects the PCM application areas and the performance of the system integrated with PCM. The melting temperature range of PCM is usually measured by a differential scanning calorimeter (DSC) with the dynamic measurement method. Unfortunately, the measurement results with this method are dependent of the heating rate. Determination of the melting temperature range of PCM means to find the starting melting temperature at which PCM starts melting and the ending melting temperature at which the melting process is finished. In this paper, a new DSC measurement method, which is the partially-melted DSC measurement method, was proposed to determine the ending melting temperature of PCM. With this method, the actual ending melting temperature of the sample PCM was found out and it was independent of the heating rate. Because there was no clear boundary between the non-melted state and the partially-melted state, the actual starting melting temperature of PCM was not able to be determined accurately.