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The simple device is made solely of fused quartz tubing and the basic tube arrangement is shown in
Figure 4.21. It is seen that the device is easy to construct, simple to operate and can be very compact.
The authors demonstrated the use of the total TGA/GC/FTIR/MS apparatus by using it to examine the
thermal degradation of poly-(a-methyl styrene), a styreneisoprene block copolymer, and showed how it
could be used to identify the decomposition products.
In anothe example of the TGA/GC/FTIR tendem combination, the Perkin Elmer Model 7 TG
instrument was used and samples of 3-4 mg were employed for the analysis. The furnace was operated
at a nominal heating rate of about 25°C per min. An HP-5 column 2.1 m long and 0.32 mm I.D was
used for the GC/IR work and one 1.7 m long, 0.1 mm I.D column for the GC/MS analyses. These short
columns provided very fast analyses and thus the thermal decomposition could be monitored extremely
precisely.
Figure 4.22
Chromatogram Obtained from the
Pyrolysis of Polyethylene at 1000°C
Courtesy of the Perkin Elmer Corporation
