Differential Scanning Calorimetry (DSC)

Differential scanning calorimetry (DSC) measures Specific Heat Capacity, Heat of Transition, and the Temperature of Phase Changes and Melting Points. DSC measures the rate of heat flow, and compares differences between the heat flow rate of the test sample and known reference materials. As a sample undergoes a transition (melting, crystallization, etc.), heat is absorbed or emitted. This change in heat flow is then measured by the system and can be analyzed. The difference determines variations in material composition, crystallinity and oxidation.

What is the process for evaluating a DSC sample?

Differential Scanning Calorimetry or DSC is a thermo-analytical technique in which the difference in the amount of heat required to increase the temperature of a sample and reference is measured as a function of temperature. Both the sample and reference are maintained at nearly the same temperature throughout the experiment. Generally, the temperature program for a DSC analysis is designed such that the sample holder temperature increases linearly as a function of time. The reference sample should have a well-defined heat capacity over the range of temperatures to be scanned.

DSC analysis determines:

  • Tg Glass Transition Temperature: o Temperature (°C) at which amorphous polymers or an amorphous part of a crystalline polymer go from a hard brittle state to a soft rubbery state
  • Tm Melting point: Temperature (°C) at which a crystalline polymer melts
  • Δ Hm Energy Absorbed (joules/gram): Amount of energy a sample absorbs when melting
  • Tc Crystallization Point: Temperature at which a polymer crystallizes upon heating or cooling
  • Δ Hc Energy Released (joules/gram): Amount of energy a sample releases when crystallizing