Analyzing Ceramic Composite Materials Using Pyrolysis

Advanced Composite Materials, also known as Advanced Polymer Matrix Composite, are widely used in the automotive industry. There are different classifications of the composites based on their matrix phase. One of these classifications is Ceramic Matrix Composites, which has several applications in the automotive manufacturing industry, like brake disks. The following tech brief describes how the PY-GC/MS technique can be used to analyze ceramic composite materials in the automotive industry.

The example shown here is the analysis of a ceramic composite material in which various additives have been added to aluminum oxide during the manufacturing process. A ceramic composite material was analyzed using a Frontier EGA/PY-3030D Multi-Shot Pyrolyzer shown in Figure 1 below.

In this technique, the sample is dropped into the furnace set at a relatively low temperature. The furnace is then programmed to a much higher temperature. Compounds “evolve” from the sample as the temperature increases and then a plot of detector response versus furnace temperature is obtained. In this experiment, to obtain the EGA thermograms, the pyrolyzer furnace temperature was programmed from 100 °C to 500 °C at the rate of 20 °C/min

Fig. 1. shows the EGA curve and average spectra of peaks A, B, C, and D observed for the composite material. Background (BG) noise has been subtracted from the average spectra. A search engine and library called F-Search from Frontier Laboratories is used for identifying the unknown compositions. There are 4 unique libraries:

• Additives-MS library
• EGA-MS library
• PY-GCMS library
• Pyrolyzates-MS library

The libraries include both chromatographic and mass spectral data. The F-Search Engine Figs. 1a and 1b show the results of library search using the F-Search EGA-MS for the spectra obtained. Peaks C and D were found, with high hit rates, to be PBMA and PS, respectively. Peak A and B are considered to be of low boiling compounds because of their lower elution temperatures. Therefore, upon searching normal MS library, peak A was judged to be a phthalate ester, and peak B saturated hydrocarbons. Library search with a combination of MS library and F-Search EGA-MS library as shown here is extremely useful as the primary search method to estimate the composition of unknown Advanced Composite Materials.

In Summary

The Frontier Multi-Shot Pyrolyzer is one of the most efficient techniques for identifying the components in advanced composite materials. It provides the scientist with a clear picture of the sample’s composition by identifying its thermal zones and the compounds in each zone. After obtaining the EGA thermogram, the appropriate temperature range for analyzing and identifying the sample’s composition can be programmed. The Frontier Multi-Shot Pyrolyzer allows multiple analysis on a single sample. There is no need for solvent as solid samples can be directly introduced to the pyrolyzer for analysis.

In addition, F-search displays TIC and mass chromatogram on a single screen and allows the user to subtract background or surrounding peaks from the targeted peak to obtain a high-quality mass spectrum. There are 700 polymers stored in EGA-MS polymer library, 700 polymers for Py GCMS polymer library, 165 polymers for Pyrolyzates-MS library, and 494 additives in Additive -MS library.

References:

1. This technical note was developed by Frontier Laboratories Ltd. 4-16-20 Saikon, Koriyama, Fukushima, 963-8862 JAPAN.
   http://www.frontier-lab.com/.