The Elimination of NO2 from Mixtures
of the Nitramines HMX, RDX and CL20
with the Energetic Binder Glycidyl Azide Polymer
(GAP) A Computational Study I

 

Manfred A. BOHN

Fraunhofer Institut für Chemische Technologie,
Energetic Materials Stability, Joseph-von-Fraunhofer-Str. 7,
D-76327 Pfinztal (Berghausen), Germany

Anton HAMMERL, Kate HARRIS and Thomas M. KLAPÖTKE

Department of Chemistry and Biochemistry,
Ludwig-Maximilians Universität München (LMU),
Butenandtstr. 5-13 (D), D-81377 München, Germany

Abstract: The energetic plasticizer glycidyl azide polymer (GAP) is used for new
types of rocket propellants which are formulated with the objective of achieving
higher burning rates. The reaction profiles for several possible initial steps in the
decomposition of mixtures of the nitramines octahydro-1,3,5,7-tetranitro-1,3,5,7-
tetrazacyclooctane (HMX), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and
hexanitrohexaazaisowurtzitane (CL20) with a monomer of GAP-diol have been
examined computationally. Comparison of the activation energies for the
decomposition of the mixtures with those for the decomposition of the isolated
nitramines shows that the presence of GAP-diol decreases the activation energy
for the elimination of NO2 by at least to 8 kJ mol-1 for CL20, wheras the NO2
elimination from HMX is only favored by 1 kJ mol-1 and NO2 elimination from
RDX is inhibited in the presence of GAP-diol by 2 kJ mol-1.

Keywords: calculation, decomposition, energetic binder, nitramine, solid rocket
propellants