Temperature modulated differential scanning calorimetry – extension to high and low frequencies

• Frequency range extension towards high and low frequencies of temperature modulated DSC.
• Simple temperature-time profile consisting of temperature steps and isotherms.
• Multi frequency analysis.
• Applicable to chip and Calvet calorimeters.
• Influence of the sample mass and general limitations are discussed.

Common temperature modulated DSCs are limited in the accessible frequency range to about 0.1–0.001 Hz. We describe an extension of this frequency range towards lower and higher frequencies by using conventional DSCs (without TMDSC option). By applying steps in the temperature-time profile a simultaneous multi frequency analysis of the heating rate and the heat flow rate response yields heat capacity data over about 2 orders of magnitude in frequency from one single measurement. Based on this step response analysis we show on the example of a Calvet calorimeter, Setaram BT 2.15, an extension down to 10−5 Hz and on the example of a chip calorimeter, Mettler Toledo Flash DSC 1, an extension up to 150 Hz. Details of the experimental procedures are provided and the influence of sample size on the obtained data and general limitations, particularly regarding temperature assignment, are discussed. A relaxation map is used to combine all calorimetric data and to compare them with dielectric data.

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