Thermogravimetric Analysis (TGA)

Expert TGA Services

What is Thermogravimetric Analysis?

Thermal Gravimetric Analysis (TGA) uses a highly sensitive balance to monitor the Weight Loss of a sample vs Time, Temperature, and Gas Environment. FAI also collects heat flow information (SDTA) to determine whether events are endothermic or exothermic and to provide accurate calibration using the melting points of high purity metal standard reference materials. 99.999% or higher purity Gallium, Indium, Zinc, Lead, Tin, and Silver are used for the most accurate calibration.

How does TGA help me?

What TGA gives us is a wealth of chemical information. From the temperature at which the weight is lost at we can determine what is being lost. How much weight is lost tells us how much was there. There are nearly limitless uses for Thermogravimetric Analysis. TGA can be used to analyze Tire Rubber Chemistry, determine the carbon black content of a masterbatch, determine the composition of a cosmetic, understand thermal stability of pharmaceuticals, find the triggering temperature of a blowing agent, determine the melting temperature of gold alloy solders, find the vapor pressure curve for lubricants, and more. Call us or request a quote to see if we can help you.

Our Equipment

FAI uses the Mettler Toledo TGA 850 with the Robotic Autosampler and the Automated Gas Switching System. This system controls the heating rate from 0ºC/minute (isothermal) up to 50ºC/minute and from room temperature up to 1100ºC.

How large is a TGA sample?

The required sample size is usually 10 to15 milligrams for each run. Samples are run in duplicate for consistency. Frequently, the ash generated at the end of a run can be used for further elemental analysis by SEM-EDXS. FAI provides a full report including plot of percent sample weight lost vs. temperature.

Controlled Vacuum ThermoGravimetric Analysis (Vac-TGA)

What is Vacuum TGA?

FAI has the rare ability to perform Vacuum Thermogravimetric Analysis (Vac-TGA). Vacuum TGA allows a sample to be analyzed at pressure conditions as low as 5.0 torr (0.0066 atm) for customer’s applications that require reduced pressure conditions in their usage. This technique is used to solve highly specialized problems in industries where low pressure is encountered during service. Vac-TGA also gives you a more accurate look into volatiles, degradation, and off-gassing of materials such as films, composites, epoxies, and more. Vacuum TGA establishes extrinsic values that provide a solid understanding of how a sample will react in the conditions applied to it in the industrial setting.

By running the same sample in normal atmospheric pressure and again under vacuum, we are able to differentiate volatization from degradation. Components that volatize will leave the sample at relatively low temperatures. Degradation is essentially unaffected by the vacuum as compared to a high purity inert gas such as nitrogen.

Further Applications: Vapor Pressure Curves

Thermal Gravimetric Analysis (TGA) run at controlled levels of vacuum also allows the generation of Vapor Pressure Curves for liquids. These fundamental properties are needed for chemical engineering applications, aerospace applications and for anything where a vacuum can be encountered in service.

Since our Mettler Toledo TGA 850 collects heat flow information (SDTA) we can determine when samples boil. The endothermic onset as well as sample weight loss signal the boiling point. Example vapor pressure curves are shown below.

Related Services:

Differential Scanning Calorimetry