TGA (thermogravimetric analysis, sometimes called thermal gravimetric analysis) and DSC (differential scanning calorimetry) are thermal analysis techniques used to determine a material’s physical and chemical properties as a function of temperature.

TGA measures changes in mass as a sample is heated, cooled, or held at a constant temperature. DSC measures the heat energy absorbed or released by a sample as a function of temperature or time, providing information about its physical and chemical properties.

Although both techniques are excellent for characterizing materials, combining them in a simultaneous thermal analyzer (STA) that performs both TGA and DSC provides a more comprehensive understanding of material properties.

TGA/DSC, or Thermal Gravimetric Analysis/Differential Scanning Calorimetry, is an important technique used in material characterization. It is commonly used in research and extensively in the polymer, chemical, battery, renewable energy, pharmaceutical, and food industries.  A TGA/DSC instrument operates over a large temperature range, typically from room temperature to 1600 °C.

TGA results provide information about the change in weight of a sample as it is heated, which is useful for determining material composition, purity, decomposition, and thermal stability. DSC provides information about the heat flow (energy) into or out of a sample as it is heated, cooled, or held at a constant temperature, which is useful for studying thermal events such as the glass transition, phase changes, and chemical reactions. These techniques can be combined into a single TGA/DSC analyzer to study a variety of materials, including polymers, composites, battery components, chemicals, metals, foods, ceramics, and pharmaceuticals. It is particularly useful in the fields of new material development, failure analysis, and quality control.

The information obtained from TGA/DSC analysis can therefore be used to optimize manufacturing processes, improve product performance, and ensure regulatory compliance. It can also help to identify potential safety concerns, such as the presence of hazardous materials or unexpected reactions.

Overall, TGA/DSC analysis is a powerful technique that provides detailed information about a wide range of material properties, helping to improve quality and safety. This can aid identification, material selection, design, and optimization across many industries, as well as facilitate academic and industrial research.

TGA/DSC analysis is widely used in the pharmaceutical industry to characterize drug substances, active ingredients (APIs), excipients, and formulations.

TGA can determine the moisture content, purity, and stability of a substance, as well as measure the degradation and decomposition of formulations under different conditions. DSC, on the other hand, can be used to examine the thermal behavior of drug substances and excipients, including melting, crystallization, glass transition temperature, and interactions.

These techniques play a vital role in formulation development, stability testing, and quality control in the pharmaceutical industry. More information can be found in the free webinar, Thermal Analysis of Pharmaceuticals.

METTLER TOLEDO's TGA/DSC simultaneous thermal analyzers offer several advanced automation features to increase efficiency. The TGA/DSC equipment is designed to seamlessly integrate with the thermal analysis sample robot, which automatically handles up to 34 samples, even if each sample requires a different method, crucible type, and evaluation. Once programmed, the sample robot operates automatically and reliably, without manual intervention, streamlining your workflow and increasing efficiency.

Additionally, the STAR^e software offers even more time-saving automation features. The following can all be performed automatically: using pre-defined limits for consistent curve evaluation, result assessment and tracking, curve comparisons, sending results to material-specific tables, timesaving FlexCal™ adjustments, and reporting. All this while ensuring compliance with industry regulations, such as 21 CFR Part 11.

Simultaneous TGA/DSC analysis is just one of many thermal analysis techniques that can be used to study the physical and chemical properties of a material. Other techniques include thermomechanical analysis (TMA) and dynamic mechanical analysis (DMA). Each technique has its own strengths and limitations. The choice of technique depends on the specific properties being studied.

TGA/DSC analysis is a versatile technique, providing information about material composition, thermal stability, transitions, and chemical reactions

TGA/DSC analysis can be used for quality control in manufacturing processes by providing information about the physical and chemical properties of a material, as well as its thermal behavior, during all stages of the production process. For example, it can be used to inspect or identify incoming raw materials as they are delivered to a production plant, to check partially finished materials during production, and for quality inspection of the finished product.

TGA is particularly useful for determining the purity and composition of materials.  DSC is used to confirm the correct thermal behavior of a material at the desired temperature, such as the glass transition, melting, and curing. When TGA and DSC are combined in simultaneous thermal analysis, they provide a more detailed and comprehensive analysis of the material.  Overall, these techniques can help ensure consistency and quality in manufacturing processes by identifying potential problems early and allowing for adjustments to be made.

Combined with the STAR^e software Quality Control option for automated curve comparison, tracking, and monitoring statistics, the TGA/DSC analyzer is an invaluable tool in the manufacturing process.

TGA/DSC analysis can be used to study a wide range of materials, including polymers, composites, metals, ceramics, adhesives, oils, pharmaceuticals, foods, biopolymers, and biofuels. This technique is particularly beneficial for studying materials that exhibit changes in mass as a result of a change in temperature or atmosphere. TGA/DSC methods are highly sensitive to even minor changes in material properties, making it a valuable tool for materials characterization in both research and quality control environments.

The application of TGA alone is generally more limited than DSC because it provides only the weight change of a material, rather than displaying the endothermic and exothermic heat flow into or out of the sample. For example, melting is an endothermic reaction, but there is no change in weight of the sample so it cannot be detected by TGA alone. TGA alone is primarily used for studying decomposition, thermal stability, and purity of materials, but cannot detect phase changes. Simultaneous TGA/DSC provides much more information about a material.