Identification Method of Aviation Nitrile Butadiene Rubber Based on Fourier Transform Infrared Spectroscopy

The numbering rules of aviation nitrile butadiene rubber (NBR) were introduced, and the theoretical basis of quantitative identification of aviation NBR by fourier transform infrared spectroscopy (FTIR) was analyzed. After the samples of aviation NBR were extracted with absolute ethanol and dried, the semi quantitative correspondence relationship between the absorbance ratio R of characteristic absorption peak (-C≡N group and -CH=CH₂ group) in spectrum and the content of acrylonitrile (CAN) in rubber raw rubber and indentification of rubber types was analyzed by infrared quantitative method. The results show that the higher the content of CAN is, the higher the absorbance ratio R of characteristic peak is. According to the R value, the type of raw NBR can be inferred. Combined with the vulcanization hardness of NBR, the aviation NBR can be further identified. For NBR with different types of raw rubber, some characteristic functional groups can be used as the basis for rubber identification.