TGFTIR

TGFTIR, short for thermogravimetric Fourier-transform infrared spectroscopy, is an analytical technique that combines thermogravimetric analysis (TGA) with Fourier-transform infrared spectroscopy (FTIR) to study materials as they are heated and to identify gases evolved during thermal treatment. The method is used to elucidate decomposition mechanisms, assess thermal stability, and characterize volatile products formed during heating.

Principle and approach: A sample is weighed in a TGA furnace while being heated according to a programmed temperature profile. As the sample loses mass, the evolving gas stream is directed through a heated transfer line into an FTIR gas cell, where infrared spectra are recorded. By correlating mass-loss events with spectral features, specific volatile species can be identified and linked to particular decomposition steps, yielding evolved gas analysis (EGA) information.

Instrumentation: A typical TGFTIR setup includes a microbalance-based TGA, a furnace with controlled atmosphere, a heated transfer line, an FTIR spectrometer with a gas-cell interface, and software to synchronize and interpret the TG and FTIR data. Some configurations couple TGFTIR with mass spectrometry (TG-FTIR-MS) for enhanced sensitivity and species confirmation.

Applications: The technique is widely used in polymer science, materials engineering, and catalysis to characterize thermal stability, decomposition pathways, and volatile byproducts. It supports polymer recycling studies, flame retardant evaluation, and the analysis of inorganic and composite materials.

Limitations: Challenges include spectral overlap of absorption bands, interference from water and CO2, and limited sensitivity for trace species. Proper calibration, background subtraction, and sometimes complementary methods are employed to improve interpretation.