3P-43 PDF
Identification of additives in a molded nitrile rubber by PY/GCxGC/HRMS
A variety of additives can be added into the raw polymer resin in order to achieve the required characteristics for the product. Likewise, if the additive concentrations are not uniformly distributed into the polymer material during the production process, then it is likely that the polymer will not exhibit the expected design characteristics. Therefore, it is important to know the distribution of additives in the molded polymer.
In this study, we identified the additives and their distribution within a commercial nitrile rubber (NBR) X-ring. Each piece was then measured without further sample preparation by using pyrolysis / comprehensive two-dimensional gas chromatography / high-resolution mass spectrometry (PY/GCxGC/HRMS). The additives benzothiazole was assigned in the results by using a NIST library search of the EI mass spectra. It should be noted here that when a single GC column is used, the identification of benzothiazole is very difficult because this compound completely coelutes with a NBR thermal decomposition compound. To further complicate this situation, the abundance of this compound is very low relative to the interfering thermal decomposition product. However, the benzothiazole was easily separated chromatographically by the addition of a 2nd column (GCxGC conditions). We will show the other additives assignment and their distribution within a X-ring.