What is Thermal Analysis?

Thermal analysis is a branch of material science that studies how a material’s properties change with temperature. From safe medicines to durable airplanes, countless products are made possible through thermal analysis. Understanding a material’s behavior under different temperatures is crucial for the successful design, processing, end use, and recyclability of completed products.

Thermal analysis is therefore important to a wide variety of industries, including polymers, composites, pharmaceuticals, batteries, electronics, foods, and inorganic and organic chemicals. Thermal analysis answers critical questions such as:

• How will my product behave under low or high temperatures, when exposed to humidity, or under mechanical stress?
• What is the operating temperature limit for my product, and what happens if it is exceeded?
• What are the best processing conditions for my material?
• How can I design my product for ultimate safety and reliability?
• What is the composition or purity of my incoming polymer or resin?
• How can a product be recycled?

Thermal analyzers typically measure heat flow, weight change, dimension change, or mechanical properties as a function of temperature, pressure, time and atmosphere. The right instrument for your lab depends on the properties you need to measure.

Properties characterized by thermal analysis instruments include:

• Melting
• (Re-)Crystallization
• Glass transitions
• Cross-linking
• Oxidation
• Decomposition
• Volatilization
• Coefficient of thermal expansion
• Loss and Storage Modulus (solid elastic behavior)
• Wetting and drying

These experiments allow the user to examine end-use performance, molecular structure and mobility, composition, processing, and stability.

There are five core thermal analysis techniques that each measure different material properties under temperature:

• Differential Scanning Calorimetry (DSC) measures exothermic or endothermic heat flows associated with thermal transitions as function of temperature, time, and atmosphere.
• Thermogravimetric Analysis (TGA) measures weight change and the rate of weight change as a function of temperature, time, and atmosphere.
• Simultaneous DSC and TGA (SDT) combines the two techniques to simplify interpretation of complex events.
• Sorption Analysis measures the weight change of a solid or liquid sample due to ab- or adsorption under controlled temperature, humidity, atmosphere composition, and pressure.
• Thermomechanical Analysis (TMA) measures changes in the dimensions of a sample as a function of time, temperature, and force in a controlled atmosphere.
• Dynamic Mechanical Analysis (DMA) measures the mechanical properties of materials as a function of time, temperature, and frequency.

There are also high-pressure DSC and high-pressure TGA for simulating high-pressure application environments.

Choosing the right thermal analysis technique depends upon the material and property you need to measure. For example, DSC is ideal for studying polymer curing, while DMA supports durability studies in electronics.

For a complete handbook covering the different thermal analysis techniques broken down by application, read our free Thermal Analysis Selection Guide. Learn how thermal analysis supports successful material development and quality control for your specific application, and whether you should combine techniques for complete characterization.