Pyrolysis behaviors of poly(acrylonitrile-co-butadiene) with differing microstructures

Pyrolysis behaviors of acrylonitrile-butadiene rubber (NBR) with different acrylonitrile contents were studied using pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) at 600–1000 °C. Structures of the pyrolysis products were determined with their mass spectra. The major pyrolysis products were butadiene, acrylonitrile, benzene, 1,4-cycloheptadiene, 4-vinylcyclohexene, cyclopent-3-enecarbonitrile, benzonitrile, and cyclohex-3-enecarbonitrile. The matching pyrolysis temperatures, at which the pyrolysis product ratios of acrylonitrile and butadiene are the same with the molar ratios, of the NBRs were different each other. The relative intensities of acrylonitrile and benzonitrile were increased by increasing the acrylonitrile content of SBR while that of 4-vinylcyclohexene was decreased. The relative intensities of acrylonitrile and benzonitrile were also enhanced with increasing the pyrolysis temperature whereas that of the 4-vinylcyclohexene was reduced.