Identification of Aeronautical Nitrile Rubbers Based on ATR-FTIR

Aeronautical nitrile rubber (NBR) was taken as the research object. The theoretical basis for identification of NBRs by ATR-FTIR was analyzed. The rubber samples were extracted by absolute ethyl alcohol, dried and quantitatively analyzed by spectrum. Then for different aeronautical NBRs, the semi-quantitative corresponding relationship between the absorbance ratio R_2237/967 of —C≡N absorption peak to —CH=CH₂ absorption peak and the content of acrylonitrile was statistically analyzed. The results show that the R_2237/967 range of nitrile-18 NBR is 0.089~0.095, the R_2237/967 range of the mixture of nitrile-18 NBR and nitrile-26 NBR is 0.146~0.149, and the R_2237/967 range of nitrile-40 NBR is about 0.224. The higher the content of acrylonitrile is, the greater the R_2237/967 is. NBRs can be further identified according to R_2237/967.