Analysis of Tire Rubber (GC-MS)
A number of additives are used in tire rubber. A combination of evolved gas analysis (EGA) and instantaneous thermal decomposition makes the qualification of these components easy.
In the example shown below, the double-shot method was used to analyze tire rubber. EGA was performed at constant temperatures between 50° C and 500 °C, where two peaks were detected (Fig. 1).
The components in the first peak are volatile, while the components in the second peak are the polymer matrix.
When using the normal instantaneous thermal decomposition method, these components appear at the same time, making their qualification difficult. Based on this EGA curve, the first thermal desorption conditions were set to 300°C (30 s) and the second instantaneous thermal decomposition conditions were set to 550°C (Fig. 2).
This system conducts GC/MS analysis of the thermal decomposition products of polymer compounds such as plastics, rubber, and resins at decomposition temperatures of 500°C and above. The decomposition products reflect the structure of the original polymer compound. Analyzing these products permits the identification of the polymer and more sophisticated structural analysis. Database search software supports the identification of polymers.