An introduction to temperature modulated differential scanning calorimetry (TMDSC): a relatively non-mathematical approach

The purpose of this paper is a rather general overview of the principles of temperature modulated differential scanning calorimetry (TMDSC). The technique is compared to conventional DSC, and particular attention is paid to whether or not the heat flow in TMDSC may be separated into so-called thermodynamic and kinetic components. It is shown that in general it is not valid to make such a separation, and that in some cases to do so may lead to confusion. The problem of applying TMDSC in transition regions is considered in the light of the need to maintain a quasi-constant structure within any one modulation period, for which a knowledge of the molecular timescale is required. The view presented here is that either this is not normally known “a priori” or it must be deduced from an appropriate kinetic theory, and hence that the technique of TMDSC will always suffer from this limitation.