Chemical Bond Between Stabilizers and HTPB Binders in Propellants

The character of the chemical bond between stabilizers and isocyanates used to cure the HTPB binder was determined. The aim was to explain, why it is not possible to extract some stabilizers from the binder of rocket motors. Investigations were performed by H-1-NMR-spectroscopy on various combinations of stabilizers and isocyanates used to cure HTPB. It was demonstrated that stabilizes of some type can be attached to the polymeric network via a reaction with the diisocyanate. Criteria to evaluate the possibility of bonding the stabilizer to the network are derived. Finally the implication of the chemical bonding on the stabilizing effect is discussed.