Differential Scanning Calorimetry

Differential scanning calorimetry (DSC) is the most frequently used thermal analysis technique. DSC measures enthalpy changes in samples due to changes in their physical and chemical properties as a function of temperature or time. Measurement principles Differential scanning calorimetry (DSC) measures the difference between the heat flows from the sample and reference sides of a sensor as a function of temperature or time. Differences in heat flow arise when a sample absorbs or releases heat due to thermal effects such as melting, crystallization, chemical reactions, polymorphic transitions, vaporization and many other processes. Specific heat capacities and changes in heat capacity, for example during a glass transition, can also be determined from the difference in heat flow. Differential scanning calorimetry (DSC) is fast and very sensitive. Sample preparation is easy and requires only small amounts of material (15±3 mg). The technique is ideal for quality control, material development and material research. DSC is the method of choice to determine thermal quantities, study thermal processes, and characterize or just simply compare materials. It yields valuable information relating to processing and application conditions, quality defects, identification, stability, reactivity, chemical safety and the purity of materials. The method is used to analyze and study materials such as thermoplastics, thermosets, elastomers, composite materials, adhesives, foodstuffs, pharmaceuticals and chemicals. Examples of thermal events and processes that can be determined by DSC Melting behavior • Curing • Crystallization and nucleation • Stability • Polymorphism • Miscibility • Liquid-crystalline transitions • Effects of plasticizers • Phase diagrams and composition • Thermal history • Glass transitions • Heat capacity and heat capacity changes • Reactivity • Reaction and transition enthalpies • Reaction kinetics • Purity