Evolved Gas Analysis that Simulates Mass Spectrometry

Mass spectrometry (MS) is a common technique to determine the degradation properties and thermal stability of polymers. However, this type of analysis, known as thermal gravimetric analysis or evolved gas analysis, can be an expensive process, is often not fully automated, and may not have enough methodological options to directly measure the effects of temperature on degradation.

A GERSTEL research team reported a method that simulates thermal gravimetric analysis with MS, by using instead the GERSTEL MultiPurpose Sampler (MPS), Thermal Desorption Unit (TDU) and Pyrolysis Insert (GERSTEL PYRO). The team also reported that this fully automated method provides a number of analytical options for sample analysis.

Combined with the MPS, the TDU PYRO is efficient and automated (up 2 x 98 samples), and can work in a variety of pyrolysis modes, including standard pulsed, sequential, and fractionated pyrolysis.

To demonstrate how the GERSTEL TDU PYRO unit is used in evolved gas analysis mode, the researchers tested four polymer samples: two Kraton® polymers (styrene block co-polymers made of polystyrene and rubber blocks), a urethane elastomer, and an acrylonitrile-styrene-acrylate co-polymer. The team then compared simulated thermal gravimetric analysis/MS data with actual thermal gravimetric analysis data.

The first derivative curve for TGA-MS on Kraton® had a shape similar to the first derivative curve for TGA. Similarly, decomposition product data using both techniques showed similar data.

The data showed that the GERSTEL MPS/TDU/PYRO system can produce data similar to thermal gravimetric analysis-mass spectrometry, making the technique suitable for evolved gas analysis. Pairing up these data with those from standard TGA can help determine thermal stability and degradation of polymers, detail small but relevant differences in composition between polymers, and help determine the optimum pyrolysis temperatures of specific polymers.

You can read the application note, “Thermal Gravimetric Analysis/Mass Spectrometry Simulation using the GERSTEL Automated Pyrolyzer” by clicking here.

After reading the details, feel free to reach out to us for a deeper conversation about how the GERSTEL Automated PYRO system could analyze thermal effects on polymers in your applications.