NMR study of molecular mobility in polysulfide oligomers and their modification products

Molecular mobility of thiokols and of some products of their modification has been studied by the nuclear magnetic resonance (NMR) method. Modification has been carried out by simultaneous heating of initial components for 30 min at 80 deg C. The NMR spectra are detected in the form of the absorption-signal derivative by the 16 MHz radiospectrometer in the temperature range from -160 to + 40 deg C. The NMR spectra of all thiokols studied in this temperature range have a single component. The temperature dependences of the thiokol absorption-line width and of its modifications are presented. The loss in mobility of the main chain of thiokols is observed almost at the same temperatures equal to -18 or -20 deg C. The whole disappearance of mobility of separate structural elements takes place at -90 deg C. It has been supposed that the above mentioned temperature range may characterize the beginning and end of devitrification of separate kinetic units of the thiokol chain