Thermal analysis techniques

The definition of thermal analysis (TA) according to the International Confederation for Thermal Analysis and Calorimetry (ICTAC), TA is a group of techniques in which changes of physical or chemical properties of the sample are monitored against time or temperature, while the temperature of the sample is programmed. The temperature program may involve heating or cooling at a fixed rate, holding the temperature constant (isothermal), or any sequence of these. Several methods are commonly used that is distinguished from another by property which is measured.


The examples of different techniques from thermal analysis as followed:

  • Differential Scanning Calorimetry (DSC) and Differential Thermal Analysis (DTA) measure thermal effects from physical and chemical processes (phase transition, reaction) and specific heat.
  • Thermal Gravimetric Analysis (TGA) measure mass change due to evaporation, decomposition and interaction with the atmosphere.
  • Thermomechanical analysis (TMA), Dilatometer (DIL) and Dynamic Mechanical Analysis (DMA) measure dimension changes, deformation, viscoelastic properties, transition and density.
  • Dielectric Analysis (DEA) measure dielectric constant (permittivity), loss factor, conductivity, resistivity (ion viscosity) and cure index (degree of crosslinking)


Basic principles of thermal analysis, the modern instrument usually consists of the following parts:

  • Sample holder or compartment for the sample
  • Sensor to detect or measure the property of the sample and temperature
  • An enclosure which the experimental parameters may be controlled
  • A computer to control data collection and processing
Image

Figure 1 Block diagram of thermal analysis instrument

The detail of each equipments will mention later.

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