• Journal of the Korean Society of Propulsion Engineers
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• v.2 no.3
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• pp.62-69
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• 1998

Mechanical properties of polyethyleneglycol(PEG)/cyclo-tetramethylene tetranitramine(HMX) propellant were studied by adding polycaprolactone(PCP) and silane derivatives as coupling agent. Mechanical properties of the propellant were enhanced by increasing the content of PCP which was partially replaced with PEG. PCP/HMX propellant showed 17% increase in maximum tensile strength and 59% increase in elongation compared to those of PEG/HMX propellant. However, as the content of PCP was increased, the hydrolytic stability of this propellant was found to be deteriorated due to the ester group of PCP by measuring hardness drop of cured propellant and swell ratio difference of PEG/PCP binder stored at $40^{\cire}C$ and 90% relative humidity. Hardness of the PEG/PCP/HMX propellant was decreased with increasing triethoxysilyl propionitrile(TESPN) and dinitrosalicylic acid (DNSA) content from accelerated aging at $60^{\cire}C$.

• Applied Chemistry for Engineering
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• v.23 no.3
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• pp.352-357
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• 2012

Techniques of thermal analyses such as DSC and TGA have been used in the study of activation energy (Ea) and frequency factor (A) depending on the particle size of RDX and HMX. Activation energy and frequency factor were calculated by Kissinger's method and Vyazovkin's method. As the particle size of RDX increased, TGA showed activation energy increased, but DSC didn't show. However, In case of HMX, as the particle size increased, both of DSC and TGA showed increase in activation energy. Moreover, Vyazovkin's method can obtain activation energy and mechanism according to decomposition of RDX and HMX.

• Korean Chemical Engineering Research
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• v.52 no.6
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• pp.706-712
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• 2014

Explosives are reactive material that contain a great amount of high potential energy. They produce detonation if released suddenly, accompanied by the production of strong light, high heat, great noise and high pressure. Damage at surrounding detonation point is affected by high pressure and blast wave for explosives detonation. Consequently, analysis of pressure and blast wave is very important. This study focuses on the analysis of maximum overpressure and blast wave of explosives for safety assurance. First of all, four cases of the amount of HMX were selected. Secondly, maximum pressure and blast wave were calculated through detonation simulation along with a set of TNT and HMX quantities. The peripheral effect of detonation point was analyzed by calculating overpressure and absolute velocity and considering detonation occurred in the center of geometry by HMX. Also, maximum overpressure and blast wave of HMX were compared to equivalent amount of TNT, which was taken as a base case and verified through theoretical HMX graph. This study contributes to the base case for overpressure and blast wave of complex gunpowder containing HMX.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1996.05a
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• pp.121-127
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• 1996

To compare the performance of aluminized solid propellants, the theoretical calculation was performed for the propellants using HTPB and PEG binder and four kinds of oxidizers such as AP, HMX, ADN, and HNIW. PEG/HMX/Al and PEG/HNIW/Al showed the maximum performance at 17% of aluminum level and there was no difference in maximum performance when HMX was partially replaced with AP in PEG/HMX/AP/Al propellant. The order of performance magnitude of various propellants which the specific impulse loss calculation was considered by semi-empirical equation was like the following; PEG/HNIW/AI>[$\frac{PEG/HMX/AI}{PEG/HMX/AP/AI}$>HTPB/AP/AI>PEG/ADN/AI

• Journal of the Korean Chemical Society
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• v.60 no.1
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• pp.9-15
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• 2016

The theoretical investigation has been performed to predict detonation velocity, detonation pressure, and thermodynamic stability of HMX/LLM-116 cocrystal. All possible geometries of HMX, LLM-116, and cocrystal have been optimized at the B3LYP/cc-pVTZ level of theory. The binding energy for the trigger bond and cluster has been calculated to predict the thermodynamic stability. The MP2 binding energies were obtained using single point energy calculation at the B3LYP optimized geometries, and the density has been calculated from monte carlo integration. The detonation velocity and detonation pressure have been calculated using Kamlet-Jacobs equation, while enthalpy has been predicted at the CBS-Q level of theory.

• Bulletin of the Korean Chemical Society
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• v.33 no.11
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• pp.3551-3553
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• 2012

1,5-Diacetyl-3,7-dinitro-l,3,5,7-tetraazacyclooctane (DADN) is a key intermediate in the preparation of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), one of the most powerful high-melting explosives. The present investigation focuses on nitrolysis of DADN to HMX by developing a new nitrolysis process involving the use of nitric acid catalyzed by Silica Sulfuric Acid (SSA). In order to optimize the process parameters for synthesis of HMX to obtain higher yield and purity, a study was carried out with variation of some parametric conditions like time, mole ratio of SSA and nitric. This method gave us green and mild conditions for nitration reaction.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.11a
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• pp.283-287
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• 2008

The heat released during the external frictional motion is a factor responsible for initiating energetic materials under all types of mechanical stimuli including impact, drop, or penetration. We model the friction-induced ignition of HMX, RDX and AP/HTPB propellant using the BAM friction apparatus and one-dimensional time-to-explosion apparatus whose results are used to validate the friction ignition mechanism and the deflagration kinetics of energetic materials, respectively. The ignition times for each energetic sample due to friction are presented.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.1
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• pp.82-88
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• 2009

The structure of steady wave system is considered which is admitted by the continuum equations for materials that undergo phase transformations with exothermic chemical reaction. With its theoretical basis in one-dimensional continuum shock structure analysis, the present approach estimates the micro-width of waves associated with phase transformation phenomena, n-heptane is selected as the hydrocarbon fuel for evaporation and condensation analysis while HMX is used for melting and freezing analysis of solid rocket propellant. The estimated thickness of evaporation - condensation front of n-heptane is on the order of $10^{-2}$ micron while the HMX melting - freezing front thickness is estimated at 1 micron.

• Journal of Mechanical Science and Technology
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• v.15 no.8
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• pp.1181-1187
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• 2001

The radiation driven response function (R$\_$q/) for AP and HMX propellant was obtained and compared with experimental results by using a simple $\alpha$$\beta$γ flame model rather than with detailed chemistry. For an AP propellant, the profile of heat release was assumed by the experimental data. The calculated R$\_$q/ shows a frequency shift of the peak amplitude to the higher frequency and a decrease in the maximum amplitude as radiation increases. In addition, it was found the increase in the total flux could enhance the mean burning rate γ$\_$b/ while the phase differences between the radiation and resulting conduction could consequently reduce the fluctuating amplitude Δγ$\_$b/. Fortunately, this is the qualitative duplication of the behavior recently observed in the experiments of RDX propellants. For HMX, the response function R$\_$q/ has been calculated and showed a quite good agreement with the experimental data. Even though the fairly good agreement of R$\_$q/ with experimental ones, the unsteady behavior of HMX was not reproduced as the radiation input increased. This is due to lack of the material properties of HMX or the physical understanding of HMX burning at high pressure.

• The Korean Journal of Physiology and Pharmacology
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• v.11 no.2
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• pp.65-70
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• 2007

Chinese herb medicines have traditionally been used to treat or alleviate the symptom of various diseases. The rationale for use of certain herbs to certain disorder is now getting unveiled by modern technology. In the present study, we investigated whether herb mix extract(HMX), which is alleged to be useful for gastric ulcer, protects stomach from oxidative stress. Rats were allowed to normal diet with and without HMX (1, 5, 10 mg/kg) for 30 days. To induce gastric ulcer, ethanol (75%, 1.5 ml) or acidified aspirin (100 mg/kg in 0.2 N HCl) was administered by oral route in 24 h-fasted rats and examined the gastric ulceration(bleeding) by measuring the size 1 h after the treatment. Results indicated the area of gastric bleeding was significantly less in HMX fed rats than in normal diet fed ones, and it was dependent on the duration and amount of HMX. To investigate the underlying mechanism by which HMX protects stomach from oxidative stress, expression of enzymes like heme oxygenase (HO), cyclooxygenase (COX), and inducible nitric oxide (iNOS) were investigated in MKN-74 cells, where aspirin or H. pylori was introduced. The results were compared with RAW 264.7 cells to check if there's cell specificities exist. The expression of HO-1 but not COX-2, iNOS was significantly increased by HMX. Furthermore, HO-1 inhibitor, SnPP IX reduced the HO-1 activity and reversed the survival rate in HMX-treated MKN-74 cells. There's no difference between RAW 264.7 cells and MKN-74 cells. We, thus, concluded that HMX is beneficial for protection from oxidative injury, and induction of HO-1 by HMX in gastric cells is, at least, responsible for protection from oxidative stress such as ethanol, aspirin and possibly H. pylori infection.