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Zhu Y.-L.,Beijing Institute of Technology | Jiao Q.-J.,Beijing Institute of Technology | Huang H.,China North Chemical Industries Group Co. | Ren H.,Beijing Institute of Technology
Gaodeng Xuexiao Huaxue Xuebao/Chemical Journal of Chinese Universities | Year: 2013

The effect of aluminum particle sizes of 10.7 μm, 2.6 μm and 40 nm on the thermal decomposition of ammonium perchlorate(AP) was investigated by thermogravimetry-Differential Scanning Calorimetry(TG-DSC). The addition of Al resulted in an increase in the temperature of the low-temperature exothermic peak and a decrease in the temperature of the high-temperature exothermic peak of AP. These changes were more pronounced with an increase in the Al content and a decrease in the aluminum particle size. The processing of non-isothermal data at various heating rates without and with 40%(mass fraction) Al was performed by Netzsch thermokinetics. The dependence of the activation energy calculated by Friedman's isoconversional method on the conversion degree indicated the decomposition process can be divided into three steps for AP and all the AP/Al mixtures determined by multivariate non-linear regression. They are C1/D1/D1(C1: 1st order autocatalysis; D1: one-dimension diffusion reaction) for neat AP, and change to C1/D1/D3(D3: three-dimension Jander diffusion reaction), C1/D1/D4(D4: three-dimension Ginst-Broun diffusion reaction) and C1/D1/F2(F2: 2nd order reaction) after addition of 10.7 μm, 2.6 μm and 40 nm into AP, respectively.


Zhu Y.-L.,Beijing Institute of Technology | Huang H.,Beijing Institute of Technology | Huang H.,China North Chemical Industries Group Co. | Ren H.,Beijing Institute of Technology | Jiao Q.-J.,Beijing Institute of Technology
Journal of Energetic Materials | Year: 2014

The method of thermogravimetry/differential scanning calorimetry-mass spectrometry-Fourier transform infrared (TG/DSC-MS-FTIR) simultaneous analysis has been used to study thermal decomposition of ammonium perchlorate (AP). The processing of nonisothermal data at various heating rates was performed using NETZSCH Thermokinetics. The MS-FTIR spectra showed that N2O and NO2 were the main gaseous products of the thermal decomposition of AP, and there was a competition between the formation reaction of N2O and that of NO2 during the process with an iso-concentration point of N2O and NO2. The dependence of the activation energy calculated by Friedman's iso-conversional method on the degree of conversion indicated that the AP decomposition process can be divided into three stages, which are autocatalytic, low-temperature diffusion and high-temperature, stable-phase reaction. The corresponding kinetic parameters were determined by multivariate nonlinear regression and the mechanism of the AP decomposition process was proposed. © 2014 Copyright Taylor and Francis Group, LLC.


Zhu Y.-L.,Beijing Institute of Technology | Huang H.,China North Chemical Industries Group Co. | Ren H.,Beijing Institute of Technology | Jiao Q.-J.,Beijing Institute of Technology
Journal of Energetic Materials | Year: 2013

The effect of aluminum particle size (10.7 μm, 2.6 μm, and 40 nm) on the thermal decomposition of 1,3,5-trimethylene trinitramine (RDX) was investigated using differential scanning calorimetry (DSC), thermogravimetry-derivative thermogravimetry (TG-DTG), and DSC-TG-mass spectrometry (MS)-Fourier transform infrared (FTIR) spectroscopy, respectively. The results showed that the first exothermic peak (512 K) of RDX diminishes gradually with an increase in the nanosize aluminum content and is overcome by the second exothermic peak when the content of nano-Al reaches 30 wt%. The reaction mechanisms demonstrated by the nonisothermal kinetics of RDX in the absence and presence of 30 wt% Al were conformed to the Avrami-Erofeev equations for all of the RDX compositions. The nucleus growth factor for the RDX/40 nm Al mixture was found to be n = 2/3 compared to n = 3/4 for RDX with and without the microsized Al. The MS and FTIR analyses indicated that the thermal decomposition of RDX in the presence of Al nanopowders favors C-N bond cleavage over N-N bond cleavage as the rate determining step. © 2013 Copyright Taylor and Francis Group, LLC.


Jiao Q.-J.,Beijing Institute of Technology | Zhu Y.-L.,Beijing Institute of Technology | Xing J.-C.,Beijing Institute of Technology | Ren H.,Beijing Institute of Technology | Huang H.,China North Chemical Industries Group Co.
Journal of Thermal Analysis and Calorimetry | Year: 2014

The method of TG-DSC-MS-FTIR simultaneous analysis has been used to study the thermal decomposition mechanism of the RDX/AP (1/2) mixture. TG-DSC showed that there were two mass loss processes for thermal decomposition of RDX/AP. The first one was mainly ascribed to the thermal decomposition of RDX. Addition of AP to RDX causes decomposition to take place abruptly, after melting, resulting in a very sharp and strong peak at lower temperature. The apparent activation energies, calculated by model-free Friedman method, of this process were negative. The second mass loss process of RDX/AP was confirmed to be the thermal decomposition of AP, catalyzed by RDX. This process can be divided into three stages, which were an nth-order autocatalytic and two onedimensional diffusion stages, respectively. There was a competition among the formation reactions of N2O, HNCO, and HCl for the first stage and between NO2 and N2O for the later two stages. The production of N2O dominated in the second stage, while NO2 did in the third stage. © Akadémiai Kiadó, Budapest, Hungary 2014.


Zhu Y.-L.,Beijing Institute of Technology | Huang H.,China North Chemical Industries Group Co. | Ren H.,Beijing Institute of Technology | Jiao Q.-J.,Beijing Institute of Technology
Journal of the Korean Chemical Society | Year: 2013

The effects of aluminum nanoparticles (AlNs) on the thermal decomposition of ammonia perchlorate (AP) were investigated by DSC, TG-DSC and DSC-TG-MS-FTIR. Addition of AlNs resulted in an increase in the temperature of the first exothermic peak of AP and a decrease in the second. The processing of non-isothermal data at various heating rates with and without AlNs was performed using Netzsch Thermokinetics. The dependence of the activation energy calculated by Friedman's isoconversional method on the conversion degree indicated the decomposition process can be divided into three steps. They were C1/D1/D1 for neat AP, determined by Multivariate Non-linear Regression, and changed to C1/D1/F2 after addition of AlNs into AP. The isothermal curves showed that the thermal stability of AP in the low temperature stage was improved in the presence of AlNs.


Zhu Y.,Beijing Institute of Technology | Xiao Z.,Beijing Institute of Technology | Jiao Q.,Beijing Institute of Technology | Ren H.,Beijing Institute of Technology | Huang H.,China North Chemical Industries Group Co.
Chemical Research in Chinese Universities | Year: 2014

Thermogravimetry-differential scanning calorimetry-mass spectrometry-Fourier transform infrared spectrometry(TG-DSC-MS-FTIR) simultaneous analysis was used to study the effects of 10.7 μm and 40 nm Al on the thermal decomposition of the Hexogen/ammonium perchlorate(RDX/AP, 1/2, mass ratio) mixture. TG-DSC results show that there are two mass loss processes for the thermal decomposition of RDX/AP/Al. The first one is mainly ascribed to the thermal decomposition of RDX. The reaction rate of RDX/AP/10.7 μm Al is so fast that the apparent activation energy, calculated by model-free Friedman method, is negative, which is the same as that of RDX/AP. 30%(mass fraction) 40 nm Al added in RDX/AP change the activation energy from negative to positive value. The second mass loss process of the RDX/AP/Al mixture is ascribed to the thermal decomposition of AP. This process can be divided into three stages for RDX/AP with and without Al. The kinetics model is not changed in the presence of micro-sized Al, while it is changed from CnB/D1/D1 to CnB/D1/D4 after the addition of 40 nm Al to RDX/AP. The reaction rate constant of the first stage and the end temperature of the second stage decrease, while the end temperatures of the third stage increase in the presence of 40 nm Al. The MS-FTIR results show there is a competition between the formation reactions of HNCO, N2O and NO2 during the second mass loss process. © 2014 Jilin University, The Editorial Department of Chemical Research in Chinese Universities and Springer-Verlag GmbH.


Luo Y.-F.,Xi'an Modern Chemistry Research Institute | Zhang Z.,China North Chemical Industries Group Co. | Zhou C.,Xi'an Modern Chemistry Research Institute | Li X.-Z.,Xi'an Modern Chemistry Research Institute | And 2 more authors.
Huozhayao Xuebao/Chinese Journal of Explosives and Propellants | Year: 2015

Using 1H, 4H-6-nitropyrazolo[4, 3-c]pyrazole-3-carboxy as primary material, 1H, 4H-3, 6-dinitropyrazolo[4, 3-c]pyrazole (DNPP) was synthesized via one step reaction of decarboxylation and nitration with a yield of 76.7%. Then the basic lead salt of DNPP (Pb-DNPP) and the 3, 6-dihydrazine-1, 2, 4, 5-tetrazine energetic ionic salt of DNPP (DHT-DNPP) were firstly obtained by the reaction of DNPP with lead nitrate and 3, 6-dihydrazine-1, 2, 4, 5-tetrazine, respectively. Their structures were characterized by IR, 1H NMR, 13C NMR, MS and elemental analyses. The pyrolysis reaction mechanism and cleavage reaction pathways of DNPP were investigated by MS (EI) fragmentation information. The thermal behaviors of DNPP, Pb-DNPP and DHT-DNPP were studied by differential scanning calorimetry (DSC) and thermogravimetry (TG)-derivative thermogravimetry (DTG). Results show that the peak temperatures of the exothermic decomposition reaction of DNPP, Pb-DNPP and DHT-DNPP are 256.4, 319.1 and 174.3℃, respectively, revealing that Pb-DNPP has better thermal stability than DNPP and DHT-DNPP. ©, 2015, China Ordnance Industry Corporation. All right reserved.

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