Ebook: Green Propellants

Doctoral Thesis. E-Print. Stockholm: KTH Chemical Scienceand Engineering, Royal Institute of Technology, SE-100 44, Sweden, 2010. - 77 p.
ISBN 978-91-7415-758-1
ISSN 1654-1081Abstract
To enable future environmentally friendly access to space by means of solid rocket
propulsion a viable replacement to the hazardous ammonium perchlorate oxidizer is
needed. Ammonium dinitramide (ADN) is one of few such compounds currently
known. Unfortunately compatibility issues with many polymer binder systems and
unexplained solid-state behavior have thus far hampered the development of ADN-based propellants.
Chapters one, two and three offer a general introduction to the thesis, and into
relevant aspects of quantum chemistry and polymer chemistry.
Chapter four of this thesis presents extensive quantum chemical and spectroscopic
studies that explain much of ADN’s anomalous reactivity, solid-state behavior and
thermal stability. Polarization of surface dinitramide anions has been identified as the
main reason for the decreased stability of solid ADN, and theoretical models have been
developed to explain and predict the solid-state stability of general dinitramide salts.
Experimental decomposition characteristics for ADN, such as activation energy and
decomposition products, have been explained for different physical conditions. The
reactivity of ADN towards many chemical groups is explained by ammonium-mediated
conjugate addition reactions.It is predicted that ADN can be stabilized bychanging the
surface chemistry with additives, for example by using hydrogen bond donors, andby
trapping radical intermediates using suitable amine-functionalities.
Chapter five presents several conceptual green energetic materials (GEMs),
including different pentazolate derivatives, which have been subjected to thorough
theoretical studies. One of these, trinitramide (TNA), has been synthesized and
characterized by vibrational and nuclear magnetic resonance spectroscopy.
Finally, chapter six covers the synthesis of several polymeric materials based on
polyoxetanes, which have been tested for compatibility with ADN. Successful
formation of polymer matrices based on the ADN-compatible polyglycidyl azide
polymer (GAP) has been demonstrated using a novel type of macromolecular curing
agent. In light of these results further work towards ADN-propellants isstrongly
encouraged.
Keywords: Quantum chemistry, reaction kinetics, ammonium dinitramide,high energy
density materials, rocket propellants, chemical spectroscopy, polymer synthesis.Dinitraminic acid (HDN) Isomerization and Self-Decomposition Revisited
Novel 1,3-Dipolar Cycloadditions of Dinitraminic Acid: Implications for the Chemical Stability of Ammonium Dinitramide
The Anomalous Solid State Decomposition of Ammonium Dinitramide: A Matter of Surface Polarization
On the Anomalous Decomposition and Reactivity of Ammonium and Potassium Dinitramide
The Molecular Surface Structure of Ammonium and Potassium Dinitramide: A Vibrational Sum Frequency Spectroscopy and Quantum
Kinetic Stability and Propellant Performance of Green Energetic Materials
Envisioning New High Energy Density Materials: Stability, Detection and Performance
Experimental Detection of Trinitramide
Tri-Block Copolymers of Polyethylene Glycol and Hyperbranched Poly-3-ethyl-(hydroxymethyl)oxetane Through Cationic Ring Opening Polymerization
Design of an Ammonium Dinitramide Compatible Polymer Matrix