HTPB used for propellant contains trace epoxy group which has a great effect on the mechanical properties of the products made from HTPB. By using 13C-NMR method in this paper
chemical shift of the goups in 13C-NMR spectra was first assured and the amount of the epoxy groups and the distribution of the hydroxyl in HTPB were obtained by measuring various samples. For the first time .three -unidentified peaks in 13C-NMR spectra of domestic samples were found. The contributing factors and the structure of these peaks were discussed.