Origin of PYX thermal stability investigation with calorimetric and spectroscopic methods

Gołofit, Tomasz; Szala, Mateusz

doi:10.1007/s10973-017-6554-3

Cited by 12 publications

(4 citation statements)

References 21 publications

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“…Using the main exothermic peak temperatures, the apparent activation energy Ea and pre‐exponential factor A were estimated to be 142±7 kJ/mol and 6.2⋅10 9 s −1 respectively, with correlation coefficient r 2 =0.99 . Calculated activation energy for TNBCO is smaller than typical energetic materials e. g. HNIW 183 kJ/mol , TATB 200 kJ/mol, RDX 212 kJ/mol PYX 261 kJ/mol . This observation can be use for explanation of relatively high FWHM of decomposition peak observed on DTA curve.…”

Section: Methodsmentioning

confidence: 82%

Synthesis and Energetic Properties of 1,3,7,9‐Tetranitrobenzo[c]Cinnoline‐5‐Oxide (TNBCO)

Gutowski

Gołofit

Trzciński

et al. 2019

Propellants Explo Pyrotec

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New and efficient method for synthesis of 1,3,7,9‐tetranitrobenzo[c]cinnoline‐5‐oxide (TNBCO) via direct nitration of benzo[c]cinnoline‐5‐oxide was described. TNBCO and precursor were fully characterized by using spectroscopic (IR, NMR) and thermal analysis methods (DTA/TG). Activation energy of decomposition process was calculated by using Kissinger's equation. Standard enthalpy of formation was calculated by using experimentally determined heat of combustion. Detonation parameters were calculated with CHEETAH code and are comparable or higher than those known for E‐2,2’,4,4’,6,6’‐hexanitrostilbene (HNS) and 2,4,6‐trinitrotoluene (TNT).

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Section: Methodsmentioning

confidence: 82%

Synthesis and Energetic Properties of 1,3,7,9‐Tetranitrobenzo[c]Cinnoline‐5‐Oxide (TNBCO)

Gutowski

Gołofit

Trzciński

et al. 2019

Propellants Explo Pyrotec

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“…Heat-resistant energetic materials (EMs) with excellent thermal stability can endure high-temperature environments for a long time [1][2][3]. In particular, 2,6-Bis(picrylamino)-3,5dinitropyridine (PYX) is a type of heat-resistant EM, first synthesized in the 1970s [4], that has been widely used in oil-well drilling [5,6]. As shown in Figure 1, PYX has a symmetrical molecular structure with strong intermolecular hydrogen bonds and π-bonds, and its unique structure leads to excellent molecular stability [7,8].…”

Section: Introductionmentioning

confidence: 99%

Effect of Cubic Crystal Morphology on Thermal Characteristics and Mechanical Sensitivity of PYX

Luo,

Wang,

Liu

et al. 2024

Crystals

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To investigate the influence of the cubic crystal morphology on the thermal properties and sensitivity of 2,6-bis(picrylamino)-3,5-dinitropyridine (PYX), cubic PYX (CPYX) crystals were prepared using the antisolvent method. Scanning electron microscopy (SEM), laser particle size analysis, X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) were used to characterize the morphology, particle size and structure of the prepared products. The thermal behavior, thermal decomposition kinetics, thermal safety parameters and thermal decomposition mechanism of CPYX were investigated by differential scanning calorimetry–thermogravimetry–mass spectrometry–Fourier transform infrared spectrometry (DSC-TG-MS-FT-IR) and in situ FT-IR experiments. Meanwhile, the mechanical sensitivity of CPYX was determined by means of the explosion probability method. The results showed that the product had a smooth cubic morphology and small crystal aspect ratio with an average particle size (d50) of 10.65 μm, but it had no distinct differences from the crystal structure of raw PYX (RPYX). The thermal decomposition peak temperature, the self-accelerating decomposition temperature and the critical temperature of the thermal explosion of CPYX increased by 7.2 °C, 6.1 °C and 10.4 °C, respectively, compared to RPYX. Similarly, the apparent activation energy increased by 15%. Besides these, the impact sensitivity and friction sensitivity of CPYX decreased by 36% and 20%, respectively, compared to RPYX. The decomposition process of CPYX contains two stages. The first stage involves the breakage of N-H bonds and -NO2 groups with the release of CO2, N2O, NO, HCN and H2O, followed by the thermal decomposition of the resulting intermediate and the release of CO2, N2O and HCN in the second stage.

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“…In the civil field, heat-resistant explosive is mainly used in the perforating blasting equipment of oil and gas wells. 2,2′,4,4′,6,6′-hexanitrostilbene (HNS) [ 3 , 4 , 5 , 6 , 7 ], tetranitro-2,3,5,6-dibenzo-1,3a,4,6a-tetraazapentalene (TACOT) [ 8 , 9 , 10 , 11 ], 2,2′,2″,4,4′,4″,6,6′,6″-nonanitroterphenyl (NONA) [ 12 , 13 ], 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) [ 14 , 15 , 16 , 17 , 18 , 19 ], and 2,6-bis(picrylamino)-3,5-dinitropyridine (PYX) [ 20 , 21 , 22 , 23 , 24 , 25 ] are commonly used in heat-resistant explosives. The energy level of TACOT is low and the synthesis steps are complex.…”

Section: Introductionmentioning

confidence: 99%

Facile Recrystallization Process for Tuning the Crystal Morphology and Thermal Safety of Industrial Grade PYX

Zhang

Ren

et al. 2023

Molecules

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In this study, the crystal appearance of industrial grade 2,6-diamino-3,5-dinitropyridine (PYX) was mostly needle-shaped or rod-shaped with an average aspect ratio of 3.47 and roundness of 0.47. According to national military standards, the explosion percentage of impact sensitivity s about 40% and friction sensitivity is about 60%. To improve loading density and pressing safety, the solvent–antisolvent method was used to optimize the crystal morphology, i.e., to reduce the aspect ratio and increase the roundness value. Firstly, the solubility of PYX in DMSO, DMF, and NMP was measured by the static differential weight method, and the solubility model was established. The results showed that the Apelblat equation and Van’t Hoff equation could be used to clarify the temperature dependence of PYX solubility in a single solvent. Scanning electron microscopy (SEM) was used to characterize the morphology of the recrystallized samples. After recrystallization, the aspect ratio of the samples decreased from 3.47 to 1.19, and roundness increased from 0.47 to 0.86. The morphology was greatly improved, and the particle size decreased. The structures before and after recrystallization were characterized by infrared spectroscopy (IR). The results showed that no chemical structure changes occurred during recrystallization, and the chemical purity was improved by 0.7%. According to the GJB-772A-97 explosion probability method, the mechanical sensitivity of explosives was characterized. After recrystallization, the impact sensitivity of explosives was significantly reduced from 40% to 12%. A differential scanning calorimeter (DSC) was used to study the thermal decomposition. The thermal decomposition temperature peak of the sample after recrystallization was 5 °C higher than that of the raw PYX. The thermal decomposition kinetic parameters of the samples were calculated by AKTS software, and the thermal decomposition process under isothermal conditions was predicted. The results showed that the activation energy (E) of the samples after recrystallization was higher by 37.9~527.6 kJ/mol than raw PYX, so the thermal stability and safety of the recrystallized samples were improved.

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Origin of PYX thermal stability investigation with calorimetric and spectroscopic methods

Cited by 12 publications

References 21 publications

Synthesis and Energetic Properties of 1,3,7,9‐Tetranitrobenzo[c]Cinnoline‐5‐Oxide (TNBCO)

Synthesis and Energetic Properties of 1,3,7,9‐Tetranitrobenzo[c]Cinnoline‐5‐Oxide (TNBCO)

Effect of Cubic Crystal Morphology on Thermal Characteristics and Mechanical Sensitivity of PYX

Facile Recrystallization Process for Tuning the Crystal Morphology and Thermal Safety of Industrial Grade PYX

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