Structural Analysis of Vulcanized NBR Using Swollen State, Solution State and Solid State 1H, 13C NMR Spectroscopy

Structural analyses of vulcanized acrylonitrile butadiene rubber (NBR) were performed by using solid state H-1 and C-13 NMR spectroscopy. Assignments of solid state H-1 and C-13 NMR spectra of vulcanized NBR were confirmed precisely by comparing with liquid phase H-1 and C-13 NMR spectra of swollen vulcanized NBR and solution of crude NBR. A sharp single peak at 33 ppm in C-13 NMR was assigned as a overlap peak of methine and methylene in achlyronitoril by DEPT spectra. A broad peak at 2,09 ppm in H-1 NMR was assignable to overlap of two kinds of methylene in 1,4-butadiene peaks, which were confirmed to be the methylene adjacent to methine and methylene, respectively, by 2D NMR spectra. As a result, complete assignments of H-1 and C-13 NMR spectra of vulcanized NBR were determined. In terms of the precise assignment of the spectra, the monomer composition of NBR could be determined.