Thermokinetic Analysis and Performance Evaluation of Guanidinium Azotetrazolate Based Gas Generating Composition for Testing of Solid Rocket Motor Nozzle Closures

Self Cite

Guanidinium azotetrazolate (GZT) based cool gas generator is being successfully used for a variety of applications in space exploration systems. In this work, an air heater igniter with a cool gas generating composite propellant (GGC) based on GZT was designed and developed for residue less combustion of fuel-air-oxygen mixture of the scramjet propulsion test facility. GGC was formulated with guanidinium azotetrazolate as fuel and ammonium perchlorate as oxidizer. The composition of GGC was selected based on theoretical study carried out using REAL software and the finalized composite propellant was processed and cast under vacuum. The thermal, ballistic, mechanical and safety properties of the GGC were determined. The propellant showed acceptable mechanical properties, fit for use as a pyrogen igniter composition for the present application. Hyphenated TG-GC/MS technique was used to reveal the evolved gas composition during decomposition. The propellant showed limited dependency of burn rate on pressure, with 'n' value of 0.61 and 'a' value of 1.361 mm s À 1 MPa À 1 . Based on the propellant energetics and experimentally devised burn rate law, a pyrogen igniter with an end burning propellant grain configuration, was designed, processed, and tested at stand-alone mode.

Section: Introductionmentioning

confidence: 99%

Development of a Cool Composite Propellant Based on Guanidinium Azotetrazolate for Air Heater Igniter Application

Hariharanath

Vineeth

et al. 2023

Self Cite

“…Derivation of kinetic parameters using isoconversional and different model fitting methods applying the data generated from thermal analysis studies is widely accepted and have been used successfully in the decomposition of many materials including energetic materials [37–43]. In principle, reactions involving parallel reactions with different activation energies and temperature dependence may not fit into the isoconversional method.…”

Section: Introductionmentioning

confidence: 99%

Kinetics and Mechanism of Thermal and Catalytic Decomposition of Hydroxylammonium Nitrate (HAN) Monopropellant

Agnihotri

Oommen

2021

Hydroxylammonium nitrate (HAN) monopropellant with its low sensitivity, volatility and toxicity, not only promises a safer substitute to hydrazine but also offers a higher specific impulse and a positive oxygen balance. This study primarily explores the decomposition mechanism and underlying kinetics for a newly developed cerium oxide‐based catalyst. The chemical kinetics involved in the thermal and catalytic decomposition was examined through an isoconversional method using thermogravimetric analysis (TG) data. The activation energy (Ea) was evaluated using differential isoconversional method (Friedman's method) and advanced integral isoconversional method (Popescu‐Ortega's method). To find frequency factor, compensation effect method (ACE) and intercept method (A0) were used. Advanced integral method could not provide realistic kinetic parameters while differential method predicted values similar to reported values for thermal decomposition. The values obtained for thermal decomposition were found matching with reported values obtained by other techniques which validated the methodology adopted. The reaction mechanism for both thermal and catalytic decomposition were proposed based on evolved gas analysis. The mechanism proposed was able to describe the variable kinetic parameters extracted from isoconversional method. Overall Ea of thermal decomposition of HAN was ∼95 kJ/mol. The decomposition over ceria‐based catalyst was distributed over three stages namely inception, peak and decay with Ea of ∼33 kJ/mol, ∼170 kJ/mol and ∼130 kJ/mol, respectively. Under identical conditions, iridium‐based catalyst show two decomposition stages with Ea of ∼65 kJ/mol and ∼120 kJ/mol while final stage being evaporation of HNO3. The ceria catalyst favoured N2 formation, increased decomposition of HNO3 and enhanced decomposition enthalpy.

“…Unfortunately, those tetrazole derivatives are sensitive to external mechanical stimulus, which limits their application. Besides, Guanidinium azotetrazolate (GZT) can be applied gas generating candidate owing to the low sensitivity (IS=32J, FS>360N) and good gas production (V=890 L kg −1 ) [18–20]. As a result, the highly gas‐productive and insensitive energetic salts play an important role in the application of novel agents.…”

Section: Introductionmentioning

confidence: 99%

Exploring Application of 1,2,4‐Triazole Energetic Salts: Gas Generating Agent, Propellant and Explosive Compositions

Xue

Xiong

Tang

et al. 2021

High‐nitrogen energetic salts as the functional materials could be applied to formulate second explosives, gas‐generating agents, and propellants due to their large gas and energy release after combustion. Herein, a series of the insensitive and highly gas productive 1,2,4‐triazole derivatives including 4,5,5′‐triamine‐3,3′‐bi‐1,2,4‐triazole (1) and 4,5′‐dinitramino‐5‐amine‐3,3′‐bi‐1,2,4‐triazole (4) as well as corresponding salts were synthesized and characterized. The crystal structures of 4,5,5′‐triamine‐3,3′‐bi‐1,2,4‐triazole (1), nitrate salt (2), 4,5′‐dinitramino‐5‐amine‐3,3′‐bi‐1,2,4‐triazole (4) and triaminoguanidine salt (9) were determined by X‐ray diffraction. For explosives candidates, energetic salts of ammonium (5), hydrazinium (6), hydroxylammonium (7), and triaminoguanidine (9) not only display the outstanding detonation performance (D, 8657–9120 m s−1, P, 27.78–33.39 GPa), but also show low mechanical sensitivities (IS≥20 J, FS≥216 N). Furthermore, the constant‐volume combustion experiment results reveal that 5, 6, 7, and 9 show excellent gas productivity (Pmax≥12.8 MPa) and pressure‐up rate (dP/dtmax≥164 GPa s−1). These compounds could be the efficient components of gas‐generating agents and propellants based on the calculated combustion parameters from EXPLO 5 software.