THERMOGRAVIMETRIC ANALYSIS (TGA)
Thermogravimetric Analysis (TGA) is a thermal analysis technique which tracks the change in mass of a sample as the temperature is increased over time (scanning mode) or during the course of a reaction within the sample chamber at constant temperature (isothermal mode). This can be used to identify and characterize a variety of thermal events: chemical absorption, desorption, sublimation, vaporization, combustion, reduction/oxidation, or decomposition.
APPLICATION AREAS FOR TGA:
The most common application of TGA analysis is in thermal stability, and oxidation/heat resistance evaluations of materials in a wide range of industries, including aeronautics, pharmaceuticals, semiconductor/electronics, ceramics and paints, motor vehicle engineering and many more.
In polymers, TGA can be used to quantify volatiles, fillers, or additives in a sample and evaluate their consequence on thermal properties. The technique has particularly wide use in characterizing drug candidates and flame-retardant additives to numerous materials. Also, the technique has miscellaneous applications in process development and failure analysis, which take advantage of its high-sensitivity characterization of material volatility, decomposition or reduction/oxidation kinetics, and adsorption/desorption behavior.
MEASUREMENTS with TGA:
- Weight-loss in the sample as a function of temperature change
- Thermal stability
- Heat resistance
- Oxidation resistance
- A quantitative measure of copolymers (in instances where reference standards are available), moisture content, volatile compounds, fillers and additives
USES & LIMITATIONS of TGA:
- What it is great for:
- Rapid and straightforward data collection
- Minimal sample prep required (accommodates a diversity of solid samples)
- Only a few milligrams of material is needed due to high instrument sensitivity
- Data fidelity bolstered by other thermal analysis techniques
Instruments We Use for TGA
TA Instruments TGA Q500
The TGA Q500 is a research-grade TGA instrument. It has a highly responsive, low-mass furnace designed with maximally efficient horizontal gas-purge and a specialized resistance-wound heat source. The tool is equipped with built-in, ultra-sensitive and dual-range thermobalance technology (weight sensitivity to 0.1µg; precision to 0.01 %), accommodating 0-200 mg and/or 0-1 g aliquots, with automated sample transfer to and from the furnace system. TA’s microbalance technology delivers both accuracy and precision in weight change detection with minimized baseline drift and reliable calibration over total 0-1g weight range.
Temperatures can be probed from ambient (~27 °C) to 1000 °C, with linear heating from 0.1 °C/min through 50 °C/min, and TA’s patented High-Res furnace control technology ensures the most sensitive and accurate heating experimental controls. Isothermal experiments can be performed with temperature accuracy within 1 °C using built-in, high-sensitivity controls. The system is also equipped with automated gas-switching capability, such that the purging gas species can be routinely adjusted between N2, air, He, and Ar to adapt to specific experimental needs.