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 combinatio ns of stabilizers and isocyanates used to cure HTPB. It was demonstrated th at stabilizes of some type can be attached to the polymeric network via a r eaction with the diisocyanate. Criteria to evaluate the possibility of bond ing the stabilizer to the network are derived. Finally the implication of t he chemical bonding on the stabilizing effect is discussed.