Postmelting baseline

First, we need to mention that the word baseline in differential scanning calorimetry has three basic meanings (1) the instrumental baseline, which is the DSC curve recorded with two empty pans (2) the extrapolated part of the DSC curve during a transition over which the peak should be integrated and (3) the pre- and postmelting baselines (see Section 2.7). 

For reporting the values of measurements, one needs to determine the melting point (this is the first point on the postmelting baseline, i.e., 235.1 °C in Fig. 2.47b), and the heat of fusion obtained from integration of the melting peak. 

The extrapolated ending-point of melting. This is the intersection of the closing edge of the melting peak and the postmelting baseline (Fig. 2.48). 

In order to determine AH21 — AHaii, it is necessary to extrapolate the postmelting scanning baseline down to lower temperatures. Often the extrapolated baseline interseets the premelting scanning baseline and this helps selection of T. The area under the eurve starts at and ends once melting has been completed. More details on the methods ean be obtained elsewhere. " ... 

Figure 13 An example of temperature-dependent crystallinity showing the postmelt extrapolated baseline. The table indicates the change in crystallinity as the material is heated. This information may be useful for determining processes and the material s useful working range. 

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