Migration and emission of plasticizer and its degradation products during thermal aging of nitrite rubber

The behavior of nitrile rubber during long-term thermal aging was evaluated by following the migration of low-molecular-weight additives and additive degradation products from the material. Headspace-GC-MS analysis showed that at 60degreesC the number of low-molecular-weight compounds released was rather low, but a significant increase in the number and amount of products was observed when the temperature was raised from 60degrees to 80degreesC, e.g., several degradation products of tris(2-butoxyethyl)phosphate plasticizer including 2-butoxyethanol and 1-butanol were identified. Oxidation of the plasticizer was also seen in the FTIR spectra. The color of the material changed from light brown to almost black during the aging.