Thermogravimetric Analysis (TGA)

ASTM D6370


To decide if TGA is appropriate for your polymer material testing goals, it is helpful to understand how thermogravimetric analysis works.

So, what is thermogravimetric analysis? During TGA, your sample is placed on a sample pan inside a furnace. The furnace may be filled with a variety of atmospheres, including ambient air, inert gas, oxidizing gases, vapors, a vacuum, and more, depending on the goal of the analysis.

ACE’s expert laboratory technicians increase the temperature at a constant rate to produce a thermal reaction. Throughout the heating process, data is collected and compiled as a TGA curve onto an x and y axis to display the mass of your sample versus temperature or time.

With this data, a number of analysis techniques can now be applied to reveal important insights about the behavior, composition, and characteristics of your material. The TGA curve can also be used as a supplement to differential thermal analysis to reveal information about glass transitions crystallization, melting, and sublimation.

TGA is based on thermogravimetric analysis theory, which proves that when a material is heated, its mass changes.

What is Thermogravimetric Analysis testing used for?

This test method provides a thermogravimetric technique to determine the amounts of organics (oil, polymer), carbon black, and ash (filler) in a rubber compound. The thermogravimetric technique employed during TGA analysis involves measuring the mass of a sample over time as the temperature changes. By measuring the change in mass, TGA provides important insight into various physical and chemical features of the sample.

TGA analysis is especially useful for studying the composition of polymeric materials, like:

Plastic films

Knowledge of the composition of your rubber polymer material is critical for meeting quality control and industry standards, as well as a useful tool for comparison to known materials.

Some of the features ACE can observe using TGA analysis include phase transitions, absorption, thermal decomposition, and solid-gas reactions such as oxidation and reduction.

Why is the ASTM D6370 Standard Rubber Test important?

ASTM D6370 (TGA analysis) is important for quality control testing, material screening, and compositional analysis. Due to the multi-compositional nature of polymer materials, precise, exact methods and ACE’s research-grade equipment are necessary to produce a thorough and complete analysis.

Quality control testing for rubber differs greatly across industries—the standards for consumer goods will not be the same as the standards for rubber tubing or rubber used in aerospace applications. ACE is familiar with a broad range of rubber and silicone industries and can use TGA to help you deliver the highest quality product.

TGA is also important for research and development. In a compositional analysis with TGA, your sample is compared to a known material to gain insight and to support strategies for further product development. Once we understand the composition of your material, it is simple to compare it to a range of other known materials for analysis.

Additional applications for thermogravimetric analysis include thermal stability evaluations, oxidation testing, and combustion testing. When paired with other types of analysis, TGA can be utilized to detail additional material characteristics. For example, to determine the amount of plasticizer or oil in a material sample, additional testing with ASTM D297 specific gravity testing will be required.

ACE is an ISO/IEC 17025 Accredited Independent Laboratory

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