Simultaneous Thermal Analyzer (STA)

Simultaneous Thermal Analyzer (STA) is a critical analytical technology in materials science and industrial applications. STA accounts for approximately 40% of all thermal techniques used in global materials analysis and is widely preferred especially in polymer production and quality control. In Türkiye, STA is used for composite material analysis at institutions such as ARUM (Osmangazi University Research and Application Center) and Sakarya University SARGEM, enhancing its importance in local industry and research. STA is an advanced instrument capable of performing Termogravimetric Analysis (TGA) and Differential Thermal Analysis (DTA) or Differential Scanning Calorimetry (DSC) measurements simultaneously in a single experiment, enabling high-precision monitoring of both mass changes and heat flow variations.

^{General View of the STA Instrument} (1)

In an STA instrument, the sample and reference material are placed in a furnace system equipped with a microbalance. The sample is heated under a controlled atmosphere (e.g. nitrogen, air or argon) at a programmed heating rate ranging from 0.1 to 100 °C/min. Two fundamental parameters are measured simultaneously:

• Mass Change (TGA): Changes in the sample’s mass are recorded with a sensitivity of ±0.1 µg. For example, a 20% mass loss can be observed in polymer decomposition between 300–500 °C.
• Differential Heat Flow (DTA/DSC): The heat absorption or release of the sample relative to the reference is measured with a resolution of ±0.1 µW. In DSC mode, phase transitions such as melting, crystallization, and glass transition of the sample are analyzed.

In analyses conducted under nitrogen atmosphere, oxidation reactions are reduced by approximately 10%, facilitating clearer separation of reaction mechanisms. The data acquisition software provides real-time graphs and correlated analyses.

STA is used for a wide range of materials characterization tasks:

• Polymer Industry: Determination of thermal stability, decomposition temperatures, and phase transitions of polymers (e.g., 20% mass loss between 300–500 °C).
• Ceramics and Metallurgy: Analysis of ceramic crystallization and melting points of metal alloys. In Türkiye, STA is commonly used for material durability testing in the ceramics sector.
• Composite Materials: Separation of components and detailed examination of thermal behavior; original research in this area is conducted at ARUM.
• Combustion and Oxidation Reactions: Determination of fuel combustion characteristics.
• Quality Control: Monitoring of process parameters and ensuring compliance with standards, particularly in polymer manufacturing.

Furnace: Controlled heating from room temperature to 1500 °C; heating rate of 0.1–100 °C/min.

Balance System: Microbalance with ±0.1 µg sensitivity.

DTA/DSC Sensor: Heat flow resolution of ±0.1 µW.

Gas Control Unit: Provides inert, oxidizing, and reducing atmospheres.

Software: Multi-parameter recording, automated analysis, and data correlation.

Simultaneous TGA and DTA/DSC measurements reduce experiment time by up to 50%.

Sample requirement is reduced, and direct correlation between different analyses is possible.

Atmosphere control simplifies the separation of reaction mechanisms.

In Türkiye, multi-sample analysis is increasingly common using automated sample changers.

Single-sample analysis can make statistical repetition difficult; therefore, automated sample changer instruments are preferred.

Decomposing complex thermal events can be challenging; artificial intelligence-assisted data analysis methods and statistical models are being developed and applied.