Synthesis Optimization of Guanidinium Dinitramide (GDN)

Area of Science:

• Energetic Materials Science
• Propellant Chemistry
• Inorganic and Organic Synthesis

Background:

• Dinitramide anion salts are promising oxidizers for efficient propellants.
• Guanidinium dinitramide (GDN) offers enhanced stability against moisture and improved long-term storage.
• GDN's guanidinium ion facilitates efficient reactions via decomposition by-products, achieving up to 99% yield.

Purpose of the Study:

• To synthesize and characterize various types of guanidinium dinitramide (GDN).
• To identify intermediates formed during GDN synthesis.
• To examine the thermal properties and chemical structure of synthesized GDN samples.

Main Methods:

• Synthesis of five GDN types (GDN-I to GDN-V) using different guanidine salts (acetate, chloride, carbonate, nitrate, sulfate) under hydrodeprivation.
• Identification of reaction intermediates.
• Characterization using Fourier transform infrared (FT-IR) spectroscopy.
• Thermal analysis to determine activation energy (Ea) from exothermic decomposition.

Main Results:

• FT-IR analysis confirmed the presence of characteristic guanidinium and dinitramide anion frequencies.
• Specific absorption peaks were identified for both ions, aiding structural confirmation.
• Activation energies (Ea) for GDN samples ranged from 50.94 to 62.19 Kcal/mole, determined from exothermic events above 153°C.

Conclusions:

• The synthesis of various GDN types was successful, with intermediates identified.
• FT-IR spectroscopy confirmed the chemical structures of the synthesized compounds.
• The determined activation energies provide crucial data for understanding the thermal stability and performance of these potential propellant ingredients.