Interaction and mechanism of nitrocellulose and N-methyl-4-nitroaniline by isothermal decomposition method

Propellants Explo Pyrotec

Chai

et al. 2020

Self Cite

The effects of various aniline stabilizers on the thermal stability of nitrocellulose (NC) were investigated via isothermal thermal decomposition dynamics. The pressuretime curves of NC/stabilizer composites were found to have a distinct inflection point, which was not observed on the pressure-time curves of NC. The effects of stabilizers on the isothermal thermal decomposition kinetics of NC were evaluated using Arrhenius equation and model-fitting method, and the effect of stabilizers on the storage time of NC was estimated using Berthelot equation. Results showed that the activation energy of NC/MNA, NC/ENA, NC/i-PNA, and NC/n-BNA before the inflection point were 162.9, 153.3, 147.4, and 150.6 kJ mol À 1 , respectively, which were significantly increased compared with that of pure NC (144.7 kJ mol À 1 ). Furthermore, the time required for the decomposition extent of NC/MNA, NC/ENA, NC/i-PNA, and NC/n-BNA to reach 0.1 % were 24.9, 11.2, 16.7, and 11.2 years, respectively, at 298.15 K, which was longer than that required of NC (10.6 years). UV-vis revealed that the stabilizers were almost consumed when the NC/stabilizer thermal decomposition pressure-time curve reached the inflection point. Based on the above results, the stability order was MNA > i-PNA > ENA > n-BNA as the criterion for time of the inflection point.

Section: Introductionmentioning

confidence: 99%

The Effects of Aniline Stabilizers on Nitrocellulose Based on Isothermal Thermal Decomposition

Luo

Propellants Explo Pyrotec

Chai

et al. 2020

Self Cite

“…The dynamic gas manometric system is as shown in Figure 1. The detailed components can be seen in ref 16 . The measuring range of the pressure sensor is 0–200 kPa with an accuracy of 0.25%.…”

Section: Methodsmentioning

confidence: 99%

“…The detailed components can be seen in ref. 16 The measuring range of the pressure sensor is 0-200 kPa with an accuracy of 0.25%. And the temperature control range is 0-573 K with an accuracy of ±0.5 K. The total volume of the reactor vessel and connection pipeline is 4.31 mL.…”

Section: Instrument and Measurementmentioning

confidence: 99%

“…Moreover, the error caused by condensation of gas products can be avoided, because the pressure sensor, sample tube, and pipeline between them are completely buried in the thermostatic furnace body during the measurement. At present, the self-developed gas manometric system has been successfully applied to study the isothermal decomposition of nitrocellulose (NC), 16,17 Nguanylurea dinitramide (FOX-12), 18 and other energetic compounds as well as some composite explosives, [19][20][21] and reasonable kinetic results have been obtained. Herein, the gas manometric system was adapted to investigate the decomposition process of NTO at both high and low temperature ranges.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Thermal behavior and decomposition kinetics of nitro‐1,2,4‐triazol‐3‐one by gas manometric technique

Xiao

Jia²,

Int J of Chemical Kinetics

et al. 2022

Self Cite

Isothermal decomposition kinetics play an important role in the stability assessment, risk assessment, and reaction mechanism inference of energetic materials.Herein, the thermal decomposition of nitro-1,2,4-triazol-3-one (NTO) was investigated using a self-development isothermal decomposition gas manometric device at both high and low temperature ranges. The kinetic parameters were calculated by model-free method and model-fitting method. The results show that the activation energies determined by these two methods are in good agreement.At 473-493 K, the entire decomposition process of NTO showed two distinct stages. The activation energy (E a ) and pre-exponential factor (lnA) in the first stage are 260.1 ± 11.5 kJ mol −1 and 52.5 ± 2.9 s −1 , respectively, while they are 166.0 ± 24.5 kJ mol −1 and 28.4 ± 6.1 s −1 in the second stage. At 383-423 K, the initial decomposition process of NTO was investigated. During this process, E a is 99.8 ± 3.2 kJ mol −1 and lnA is 11.5 ± 1.0 s −1 . According to the kinetic results, a mechanism was speculated to be the transition of a rate-limiting step from nucleation and nuclei growth to the gas diffusion. Moreover, the E a -lnA sets were found to lie on the kinetic compensation regression line, which indicates that the kinetic data in this work are reliable. All the results will further support and complement the kinetic database of NTO.

“…Double-base propellants contains many nitrate compounds, including nitrocellulose (NC) and nitroglycerin (NG), which decompose to generate nitroxide radicals during long-term storage. NC is a highly flammable polymer formed by nitrating cellulose via exposure to nitric acid or another powerful nitrating agent; it has usually been applied to various military and civilian applications − It is noteworthy that these nitroxide radicals accelerate the decomposition of nitrate compounds, thus deteriorating the propellant’s performance, burning, and even explosion. − The stabilizers are usually added to the propellants by absorbing the nitrogen oxides produced from nitrate compound decomposition to improve stability, thereby restraining further autocatalytic decomposition of the nitrate compounds. − The stabilizers commonly applied to double-base propellants are mainly aniline and urea derivatives, − such as diphenylamine (DPA), 2-nitrodiphenylamine (2-NDPA), N -methyl- p -nitroaniline (MNA), N , N’ -diethyl- N , N’ -diphenylurea (C1), N , N’ -dimethyl- N , N’ -diphenylurea (C2), 1,1-diphenylurea (AK-I), and 3-methyl-1,1-diphenylurea (AK-II). Among them, DPA, 2-NDPA, and MNA are basic and can rapidly combine with nitrogen oxides, inhibiting the autocatalytic decomposition of nitrate compounds and stabilizing the propellants.…”

Section: Introductionmentioning

confidence: 99%

Fullerene Stabilizer 4,11,15,30-Tetraarylamino Fullerenoarylaziridine: Regioselective Synthesis, Crystallographic Characterization Derivatives, and Potential Application as Propellant Stabilizer

Chai

Luo

ACS Appl. Energy Mater.

et al. 2020

Self Cite

The safe storage of propellants has become increasingly challenging because of extreme storage and operational environments. Hence, high-performance stabilizers should be urgently developed to improve the stability of propellants. In consideration of the stability mechanism of stabilizers and the excellent free radical scavenging ability of fullerenes, we synthesized six fullerene stabilizers, 4,11,15,30-tetraarylamino fullerenoarylaziridines, through the nucleophilic substitution reaction of hexachlorofullerene (C 60 Cl 6 ) and corresponding aromatic amines with high yields. Their structures were adequately confirmed by HRMS, FT-IR, UV−vis, 1 H NMR, 13 C NMR spectroscopy, and single-crystal X-ray diffraction. The results of methyl violet test paper and thermogravimetric analysis manifested that the stabilities of these multifunctional fullerene derivatives to nitrocellulose were remarkably better than traditional stabilizers, such as N, N′-dimethyl-N, N′-diphenylurea and diphenylamine. Further electron paramagnetic resonance spectroscopy and FT-IR analysis reasonably revealed that this excellent stability ascribed the efficient scavenging ability for nitroxide radicals produced by nitrocellulose pyrolysis, thereby inhibiting the autocatalytic decomposition of nitrocellulose.