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Crystal Properties
1. Crystal Morphology Control and Properties of Ultrafine HNS
YANG Li, REN Xiao-ting, ZHANG Tong-lai, ZHANG Jian-guo
State Key Laboratory of Explosion Science and Technology, Beijing Instituteof Technology, Beijing 100081, China
Abstract: The ultrafine HNS was prepared by solvent and non-solvent method and the controlling technology about crystal morphology, and the influencing factors about categories, dosage of surfactants and injecting styles were analyzed. Results show that the above factors have important effect on the morphology, particle size and agglomeration in the crystallization process. Injecting by syringe needle, free-running elliptoid and spherical HNS grain from 100 to 400nm were obtained in the condition of 0.40g raw materials HNS and 3.0mL 0.5% DT surfactant, and the least particle diameter with 50nm and spherical HNS grain with narrow particle-size distribution was obtained in the condition of 0.40g raw materials HNS and 1.8mL 1% polyoxyethylene ether(PT). The ultrafine particle of HNS has higher heat resisting evenness and can be ignited by black powder grain. The 50% inflammation height is about 12cm.
2. Crystal Structure and Morphology Simulation of HNS
YANG Li1, REN Xiao-ting1, YAN Ying-jun2, MU Hai-yan1, ZHANG Tong-lai1, YU Kai-bei1
1.State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081, China
2.Jiangxi Journalism and Publication College, Nanchang 330224, China
Abstract: Suitable single crystal of hexanitrostilbene(HNS) was cultured and its crystal structure was determined by X-ray single crystal diffraction method. The results show that the crystal belongs to monoclinic system with space group P2(1)/c and cell parameters of a=2.198(2)nm, b=0.5528(5)nm, c=1.4663(13)nm, β=108.632(9)°, V=1.688nm3, Dc=1.771g/cm3 and Z=4. The module of Morphology of Material Studio can be used to calculate the crystal structure and crystal facet parameter. The crystal morphology was simulated with three different calculation methods and theories. The specific crystal facet area, appendiculate energy, surface energy, the crystal facet relative growing velocity and the other parameter were obtained. The influence of main crystal facet structure and relative growing velocity on the crystal morphology of HNS in the crystal grow process was analyzed. The surfactant containing H and O in the functional group served as crystal modifier can control the crystal morphology more effectively.
3. Theoretical Study of the Effect of PNMAIW on HNIW Crystal Transition in Different Crystal Systems
LI Li-jie1, CHEN Shu-sen1, RAN Jun-peng2, WANG Hua1
1.School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China
2.Representation of PLA General Army Armament Department at Gansu Yinguang Chemical Industry Group Co., LTD, Baiyin Gansu 730900, China
Abstract: In order to reveal the effect of PNMAIW on the crystal transition of HNIW theoretically, the stability configuration of PNMAIW was designed by the methods of molecular modeling. The effect of PNMAIW on the HNIW crystal in the system of nitric acid/water, ethyl acetate/n-hexane, and ethyl acetate/chloroform, respectively, was studied. The results show that PNMAIW has four stable structures. The bonding energy of PNMAIW to the surface of HNIW is much larger than that of the solvent and the nonsolvent to the surface of HNIW, so the exist of PNMAIW in the crystal transition system would inhibit the formation of ε-HNIW crystal.
4. Preparation and Thermal Properties of FOX-7
FU Qiu-bo1, SHU Yuan-jie1, HUANG Yi-gang1, ZHOU Jian-hua1, ZHANG Yun-xiang2
1. Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang Sichuan 621900, China
2. College of Chemical Engineering, Sichuan University, Chengdu 610065, China
Abstract: In order to understand the influence of FOX-7 crystal shape and size on its thermal properties, the FOX-7 crystal was obtained from system DMF/H2O and NMP/H2O by cooling crystallization and the antisolvent crystallization.SEM results show that the obtained crystal have two shapes, namely extended tetrahedral or hexahedral prism and rhombohedral prismatic crystal. The size and contained number of particles of the crystal from different ratio system are different. The crystals shape by ultrasonic treatment was single, but the crystals surface is comparatively rough.DSC results show that the thermal properties of FOX-7 obtained by different ways and different solvent system have a certain degree of difference. This indicates that FOX7 crystal with different shapes, sizes and thermal properties can be obtained by the crystallization in different ways and solvent system. The crystals shape was controlled by ultrasonic treatment.
5. Calculated Simulation of the Crystal Morphology of HMX
TANG Zhan, YANG Li, QIAO Xiao-jing, ZHANG Tong-lai, QI Shu-yuan
School of Mechatronical Engineering, Beijing Institute of Technology, Beijing 100081, China
Abstract: The crystal morphology and crystallization behavior of HMX were calculated by using BFDH, Growth Morphology and Equilibrium Morphology contained in Morphology module of Material Studio. The structures of important crystal faces, the growth habit of the crystal and the relationship between the structures of crystal faces and surfactants were studied. The calculated results show that the results obtained by Growth Morphology and Equilibrium Morphology quite coincide with the actual results.
6. Crystal Structure of 2-Nitrimino-5-Nitrohexahydro-1, 3, 5-Triazine
ZHOU Cheng, ZHOU Yan-shui, HUO Huan, HUANG Xin-ping, JIA Si-yuan
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China
Abstract: The single crystal of 2-nitrimino-5nitrohexahydro-1, 3, 5-triazine(NNHT) was cultivated from water, and characterized by elemental analysis, IR, 1 H NMR and 13 C NMR.Its structure was determined by a X-ray single crystal diffractometer. The results show that the empirical formula is C3H6N6O4 and the molecular weight is 190.14, the crystal is monoclinic, its space group is P21/c with crystal parameters of a=0.939 3(2)nm, b=0.859 0(2)nm, c=0.901 5(2)nm, β=91.173(4)°, V=0.727 2(3)nm3, Z=4, Dc=1.737 g•cm-3, μ=0.157 mm-1, F(000)=392. The final R is 0.058 3. The structural difference of NNHT with RDX, NQ is analysed. The relationship between the structural features of NNHT and its impact sensitivity is discussed.
7. Influences of Recrystal Technology on the Impact Sensitivity of PETN
WANG Xiang-yuan, LI Wei-ming, ZHOU Xiao-wei, ZHU Yong-wei, WANG Jian-long
School of Chemical Engineering and Environment, North University of China, Taiyuan 030051, China
Abstract: Effects of solvent-non-solvent, temperature, stirring speed and dilution rate on the impact sensitivity of recrystallized PETN were studied by single factor test. The impact sensitivity of different recrystallized PETN was characterized with 50% drop height(H50). Crystal shape and surface defects of different recrystallized PETN are observed with an optical microscope and a metallographic microscope. The influence of recrystallization technology on the impact sensitivity of PETN crystal is ulteriorly analyzed from crystal shape and surface defects. Single-factor experimental results showed that PETN particle with H50 14.6 cm can be got when ethyl acetate as solvent, temperature 50℃, dilution rate 0.05 mL/min, stirring speed 100 r/min. The impact sensitivity of PETN recrystallized from ethyl acctate is much lower than that recrystallized from acetone-water in industry.
8. Prepartion and Crystal Control of Desensitized-RDX
WANG Yuan-yuan, LIU Yu-cun, WANG Jian-hua, LIU Deng-cheng
College of Chemical Engineering and Environment, North University of China, Taiyuan 030051, China
Abstract: The desensitized RDX was prepared by the method of solvent-nonsolvent recrystallization, the effect of different conditions, such as temperature, solvents, surface-active agents, stirring strength and feeding modes was studied. The results obtained by an optical microscope, SEM and the impact sensitivity test show that the crystal shape and inner quality of crystallized RDX are improved and the impact sensitivity is reduced adopting the best process conditions:70℃, DMSO-solvent, methanol-nonsolvent, dextrin-surface active agent, 1 000 r/min stirring strength. The different sizes by controlling RDX concentration of initial solution was gained. The impact test results indicate that the impact sensitivity of granuration 100-120 μm is decreased by 34%.
9. Preparation Process of Ultra-fine ∈-HNIW
WANG Pei-yong1, WANG Jing-yu1, ZHENG Cheng-yang2, HUANG Hao1, SHANG Hui1, CAO Jin-xia1
1.College of Chemical Engineering and Environment, North University of China, Taiyuan 030051, China;
2.Shanxi North Xing'an Chemical Industry Co., Ltd., Taiyuan 030008, China
Abstract: Solvent-non-solvent recrystallization to prepare ultrafine HNIW was studied. The particle size and particle size distribution of ultra-fine HNIW were resarched by changing of factors such as the volume ratio of solvent and non-solvent, solution temperature, feeding rate and ultrasonic frequency. The optimally conditions were determined with acetic ether as solvent and petroleum ether as non-solvent, and the volume ratio of solvent and non-solvent was 1∶5 and the temperature of the saturated solution of ∈-HNIW as 50 ℃, ultrasonic bath with frequency of 60 KHz.Results showed that the product was ∈ phase HNIW with particle size of approximately 1 μm.
10. Crystal Structure of 3, 4-dinitrofurazanofuroxan
ZHOU Yan-shui, ZHANG Zhi-zhong, LI Jian-kang, GUAN Xi-ren, HUANG Xin-Ping, ZHOU Cheng
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China
Abstract: The single crystal of 3, 4-dinitrofurazanofuroxan (DNTF) was cultivated from the mixed solvent of acetone and water, and was characterized by using the X-ray diffraction analysis, elemental analyses and FT-IR technique. The results show that the molecular formula is C_6N_8O_8 and the molecular weight is 312.14. The crystal is orthorhombic, space group P_(2.2.2), with crystal parameters of a=1.0746(7)nm, b=1.5099(10)nm, c=0.6596(4)nm , V=1.0702(1)nm~3, Z=4, Dc=(1.937)g/cm~3, μ=0.182mm~(-1), F(000)=624. The final R is 0.038.
11. Non-isothermal Crystallization Kinetics of TNT in HMX and RDX, Zhou Wen-jing, Zhang Gao, Liu Zi-ru, [Xi'an Modern Chemistry Research Institute, Xi'an 710065, China]
Abstract: The non-isothermal crystallization of TNT in HMX and RDX was studies by differential scanning calorimetry. The results show that HMX-HNS and RDX-HNS can reduce the super cooling degree of TNT and eliminate the self-heating in the crystallization process of TNT. The kinetic exponent n in the crystallization process obtained by Avrami equation was 2.76 in HMX and 2.86 in RDX. Ozawa exponent m and temperature function F(T) were obtained by Avrami-Ozawa equation. Ea and A of non-isothermal crystallization kinetic parameters of TNT in HMX and RDX were obtained by Kissinger′s equation and Ozawa′s equation and a comparison between the obtained results was carried out.
12. Non-isothermal Crystallization Kinetics of TNT in HMX and RDX, Zhou Wen-jing, Zhang Gao, Liu Zi-ru, [Xi'an Modern Chemistry Research Institute, Xi'an 710065, China]
Abstract: The non-isothermal crystallization of TNT in HMX and RDX was studies by differential scanning calorimetry. The results show that HMX-HNS and RDX-HNS can reduce the super cooling degree of TNT and eliminate the self-heating in the crystallization process of TNT. The kinetic exponent n in the crystallization process obtained by Avrami equation was 2.76 in HMX and 2.86 in RDX. Ozawa exponent m and temperature function F(T) were obtained by Avrami-Ozawa equation. Ea and A of non-isothermal crystallization kinetic parameters of TNT in HMX and RDX were obtained by Kissinger′s equation and Ozawa′s equation and a comparison between the obtained results was carried out.
13. Comparison Study on the Compaction Equations for RDX and HMX Granule Compression, Li Ming, Huang Hui, [Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang Sichuan 621900, China], Tan Wu-jun, [Graduate Faculty of China Academy of Engineering Physics, Mianyang Sichuan 621900, China]
Abstract: Two different re-crystallized samples and a commercial grade sample are selected to conduct quasi-static compression tests for RDX and HMX crystalline particles. The compressive stress/density curves are derived from experimental force/displacement curves. The Kawakita and Heckel equations are applied in fitting the compressive curves. The results show that the fitting constants with the reciprocal dimensions of modulus can be used as quantitative parameters to evaluate the mechanical property and crystalline quality of energetic crystalline particles. The fitting results perform excellently to distinguish the re-crystallized and commercial grade samples. Comparing the fitting results, both equations fit quite well for RDX, though there is some deviation for HMX, especially by the Heckel equation. Choosing to fit the individual data of deformation and fragmentation stage of the compressing process by two equations, the fitting process and the distinguish ability of the fitting parameters are improved greatly, proving that the Kawakita equation is better for the compaction of energetic granules.
14. Preparation of Certified Reference Material of HMX and Study on its Homogeneity, Huang Xin-ping, Zhang Gao, Zhou Cheng, Chen Zhi-qun, Zhou Yan-shui, Fu Xia-yun, [Xi'an Modern Chemistry Research Institute, Xi'an 710065, China]
Abstract: Technology on purification of HMX was studied with the industrial special-class product as primary substance, and the certified reference material of HMX prepared. The effect of re-crystallizing with different solvents on purity of HMX was studied. Two kinds of re-crystallization method and three steps operation respectively were selected to purify HMX: firstly, HMX was solvated in 80℃ with potassium permanganate, heat-filtered to remove inorganic and mechanical impurities, and separated out the HMX crystals by solvent-non-solvent precipitation technique. Secondly, the HMX crystals were re-crystallized by acetonitrile as solvent to effectively remove organic impurities RDX etc., making the HMX purity above 99.60%. Thirdly, the HMX crystals were boiled with MOS anhydrous alcohol to remove further organic impurities and solvent remainder. The results by HPLC and X-ray powder diffraction analysis show that the purity of the certified reference material of HMX is equal or above 99.70%, the crystal is β phase with good homogeneity.
15. Study on Lowering Sensitivity of RDX by Re-crystallization, Feng Xue-song, Zhao Sheng-xiang, Li Xiao-ping, [Xi'an Modern Chemistry Research Institute, Xi'an 710065, China]
Abstract: Three types of RDX crystals are prepared with NMP, DMF and DMSO as solvents. The effects of different solvents on the crystal appearance, positive hole, dislocation and residual solvents are studied. The crystal shape and inner quality of crystallized RDX are analyzed by SEM and an optical microscope. Their densities and impact sensitivities are measured by density-bottle method and 10 kg-hammer technique. The results show that, crystallized RDX from DMSO has better crystal quality, the lowest impact sensitivity 54% and the highest density 1.823 g/cm3.
16. A Granulation Classifying Process of HMX Re-crystallized by γ-Butyrolactone
Yu Xian-han, Jia Yi-ping, [Gansu Yinguang Chemical Industries Group Corporation, Baiyin Gansu 730900, China]
Abstract: A method and principle of HMX re-crystallized by γ-butyrolactone and the crystallization status of HMX in γ-butyrolactone solution under different super saturation degree were studied. The HMX products with 6 kinds of granulation conforming to GJB2335-95 were prepared through controlling of the process conditions, such as the adding rate and the amount of water used for diluting the solvent and the stirring strength during the crystallizing procedure. The results indicate that the process is simple to operate; the solvent is easy to recovery and can be recycled, having the advantages of the lower consumption and no pollution.
17. Investigation of the Dilution/Crystallization Dynamics of RDX and HMX by Microcalorimetry
HU Rong-zu~(1, 3), LI Zhi-bin~1, CHEN Xi-jun~1, ZHAO Feng-qi~1, SONG Ji-rong~2, GAO Sheng-li~3, SHI Qi-zhen~3
1. Xi'an Modern Chemistry Research Institute, Xi'an710065, China
2. College of Chemical Engineering, Northwest University, Xi'an710069, China
3. Department of Chemistry, Northwest University, Xi'an710069, China
Abstract: Three thermokinetic equations describing the crystal growth process and two relationships between the parameters and the constants of the kin-etic equations are derived. The total heat produced and the rate of heat production during the dilution/crystallization of RDX and HMX from dimethyl sulfoxide, cyclohexanone and nitric acid are measured using a Calvet microcalorimeter and a model RD-1 conduction calorimeter. The thermokinetic data of crystal growth processes of RDX and HMX are treated based on the derived equations and relationships. The results show that the exothermic dilution/crystallization processes of RDX and HMX accord with the Burton-Cabrera-Frank dislocation theory.
18. Optimal Technical Conditions of Preparing Spherical Nitroguanidine by Uniform Design
LI Wen-ying, ZHANG Wan-jun, SONG Jing-xuan
School of Electromechanic Engineering, Beijing Institute of Technology, Beijing100081, China
Abstract: Optimal technical conditions of preparing spherical nitroguanidine(NQ) had been obtained by adopting uniform design experimentation, and the spheral nitroguanidine with higher bulk density had been prepared. In the non-aqueous-solvent process of spherical nitroguanidine preparation, adding a certainty of NQ crystallization control particles into the mother liquor make the residual solution(mother liquor) reuse. The NQ crystallization control particles must be spherical, its particle size and adding quantity also must be limited in a certain range and technical conditions must be controlled in the state of crystallization of mother liquor. The technical conditions were optimized as follows: particle size and adding quantity of NQ crystallization control particles were 70-100 μm and 0.5% respectively, cooling rate of super-saturation solution was 3.5℃/min. The prepared spherical nitroguanidine particle had regular shape and smooth surface. Its bulk density and vibro-compacted density might reach 1.01 g/cm~3 and 1.13 g/cm~3 respectively
19. Impact Sensitivity of Hexanitrohexaazaisowurtzitane
JIN Shao-hua, YU Zhao-xing, LIU Jin-quan, CHEN Shu-sen, OU Yu-xiang, SONG Quan-cai
School of Science of Materials and Engineering, Beijing Institute of Technology, Beijing 100081, China
Abstract: The ε-HNIW crystals with various crystal habits and modified ε-HNIW coated with several kinds of coating materials were obtained under different technological conditions and their impact sensitivity were determined. The results show that ε-HNIW crystals with approximate parallelogram shape and identical size have lower impact sensitivity and little needle ε-HNIW crystals have the highest impact sensitivity among these samples. Wax and butadiene nitrile rubber can effectively decrease the impact sensitivity of ε-HNIW, whereas polycarbonate acrylonitrile-butadiene-styrene cannot.
20. A Study on Size Grading Process of Crystalline TNT
ZHAO Rui-xian, GAO Tian-ping, ZHENG Ying-juan
Yinguang Chemical Industrial Corporation, Baiyin 730900, China
Abstract: With the help of the crystalline process of supercooled melt TNT method (hot-water suspension) and thermodynamic law, the effect of temperature and mixing speed on the crystalline process is analyzed and the process conditions are defined. The results show that the process can produce crystalline TNT products with different size grading needed for satisfying the user. In comparision with solvent crystallization, the process has the advantages of lower material costs, no solvent recovery and no atmospheric pollution and very good economic benefits and industrialization prospects.
21. Characterization and Crystal Structure of 2, 4, 6-Trinitrochlorobenzene
MIAO Yan-ling1, ZHANG Tong-lai1, QIAO Xiao-jing1, ZHANG Jian-guo1, YU Ren-guang1, YU Kai-bei2
1. Beijing Institute of Technology, Beijing 100081, China
2. Chengdu Branch China Academy of Science, Chengdu 640041, China
Abstract: 2, 4, 6-Trinitrochlorobenzene(TNCB)single crystal was cultivated out from acetone solution, and characterized by X-ray diffraction analysis, element analysis and IR. It belongs to monoclinic space group P2(1)/c, with crystal parameters of a=1.2501(1) nm, b=0.6803(1) nm, c=1.1038 (1) nm, β=102.842(9)°, V=0.91526(15) nm~3, Z=2, Dc=1.797 g/cm~3, μ(MoKα)=0.438 /mm, F(000)=496, R1=0.039 5, ωR2=0.0991.
22. Study on RDX Granulate Stage Process
ZHAO Rui-xian, LI Guang-ming, GAO Tian-ping, LIN Yu-hui
Gansu Yinguang Chemistry Industrial Corporation, Baiyin 730900, China
Abstract: The principal factors affecting the grading process for the recrystallization of RDX from acetone are given through the orthogonal test. According to the grading standard of 4 grades product, the grading process condition of product grain is determined. The oversaturated state of solution, kind and evaporation rate of solvent affecting crystallization process are described. The grading process condition of 1～8 grades RRX are analyzed and determined, and the test is optimized. The results indicate that the recrystallization process of RDX from acetone is satisfied for the produce of RDX with different grain size.
23. Factors Affecting Particle Size in Supercritical CO_2 Antisolvent Precipitation HMX
CAI Jian-guo, DENG Xiu
Chemical Engineering Research Centre ECUST, Shanghai 200237, China
Abstract: The precipitation of 1, 3, 5, 7-tetranitro-1, 3, 5, 7-tetraazacyclooctane (HMX) in acetone solution using supercritical CO2 antisolvent and the factors affecting particle size were studied. The results show that the average particle size is decreased with the increasing of pressure. The temperature is the major reason that it cause to form α-HMX, and the average particle size is slightly increased with the increasing of temperature. As compared with pressure and temperature, the average particle size is sensitive to initial feed concentration of HMX, and the increasing of concentration will cause the increasing of particle size. The expansion speed is also a factor affecting the particle size and size distribution. The microparticle of HMX with narrow size distribution is obtained when the solution is expanded rapidly and the supersaturation ratio is consumed by mass nucleation.
24. Effect of RDX Re-crystallized RDX with Different Solvents on Mechanical Properties of Composition A5
SIMA Tianiong, YAN JiSheng
Gansu Yinguang Chemistry Industrial Corporation, Baiyin 730900, China
Abstract: The mechanical properties of composition A5 containing different types of RDX recrystallized with different solvents are investigated experimentally. It is found that the composition A5 havs obvious difference in aspect of mechanical properties since the solvent effects recrystallization mechanism of RDX considerably.
25. Experimental Study on the Spray-crystal Ultrafine Explosive HMX
WANG Jing yu, ZHANG Jing lin, XU Wen zheng
Nanjing University of Science and Technology, Nanjing 210094, China
Abstract: This paper, for the improvement of the crystallize ultrafine effect of explosive, presents a novel ultrafine method--the spray crystal method including chemical and physical action. The sub micron particle of explosive HMX was prepared through optimizing the technology condition.
26. Effect of RDX Re-crystallized RDX with Different Solvents on Mechanical Properties of Composition A5
SIMA Tian iong, YAN Ji Sheng
GanSu YingGuang chemical Industrial Complex, BaiYin.730900, China
Abstract: The mechanical properties of composition A5 containing different types of RDX recrystallized with different solvents are investigated experimentally. It is found that the composition A5 havs obvious difference in aspect of mechanical properties since the solvent effects recrystallization mechanism of RDX considerably.
27. Experimental Study on the Spray-crystal Ultrafine Explosive HMX
WANG Jing yu, ZHANG Jing lin, XU Wen zheng
Nanjing University of Science and Technology, Nanjing 210094, China
Abstract: This paper, for the improvement of the crystallize ultrafine effect of explosive, presents a novel ultrafine method--the spray crystal method including chemical and physical action. The sub micron particle of explosive HMX was prepared through optimizing the technology condition.
28. The Preparing of Size-grading products of HMX by Crystallizing in Solvent
CAO Duan-lin, XU Chun yan, ZHENG zhi hua
North China Institute of Technology, Taiyuan 030051, China
Abstract: The raw product α HMX obtained by means of acetic anhydride method is added to the mixture solvent of acetone and ethyl acetate. According to the principles of crystallization and transformation, and by proper control over technological conditions and operating methods, α HMX is thoroughly turned into β HMX with four different grades of A, C, D and F.
29. A Study of Crystal Structure and Explosive Properties of Ammonium Perchlorate
ZHANG Jian guo, ZHANG Tong lai, YANG Li
Beijing Institute of Technology, Beijing 100081, China
Abstract: In this paper, the molecular structure of ammonium perchlorate was determined by the four circle diffractometer. The crystalline is in orthorhombic with space group Pna2(1). The crystal parameter of the title compound are as following: a =0.9220(1) nm, b =0.7458(1) nm, c =0.5814(1) nm, V =0.3998(2) nm 3, Z =4, D c =1.952 g/cm 3, μ =0.831 nm -1 , F (000)=240. At the same time, the explosive properties of Ammonium perchlorate were studied by tests.
30. Process Research on Crystalline to Improve PETN Bulk Density
YU Xian han
805 Factory, Baiyin 730900, China
Abstract: Refinery PETN through re crystallization in solvent by using fatted crude PETN by concentrated nitric acid as raw material was produced. The PETN bulk density affected by different solvents, crystallization speed solution pH value was discussed.
31. Preparation of HMX microsphere
FU Ting ming, YANG Yi, LI Feng sheng
Naijing university of science & technology, Nanjing 210094, China
Abstract: HMX microsphere is prepared by wet grinding , the morphology, size distribution and degree of crystallization are studied by SEM, laser diffraction and XRD respectively .
32. A Study on the Amount of Spent Acid for Crystal Transformation with Spent Acid
WEI Tian yu, LI Zhi hua, YU Xian han
805 Factory, Baiiyin 730900, China
Abstract: By changing experimental condition, β HMX has been obtained from acetic anhydride. The amount of spent acetic acid has been lowered 25% and the period of production has been shorted 2h. It is possible that mixed solvent will be replaced by spent acid in Crystal transformation of α HMX into β HMX.
33. Radiation Effect on Relative Crystallinity of Cellulose
ZHANG Lin, GU Han quan, GAO Ren xiao
(Xi'an Modern Chemistry Research Institute, Xi'an 710065, China
Abstract: Cellulose is pretreated by radiation method using Co 60 ray as radiation source. The relative crystallinity of refined cotton cellulose was studied by IR. The results shows that the relative crystallinity of cellulose decrease with the increasing of radiation dose.
34. Study on the Preparation of Sub-micron TATB Particles Using the Crash Crystal Technology
ZENG Gui-yu, NIE Fu-de, YIN Li-sha, CHEN Ya
Institute of Chemical Materials, CAEP, Mianyang 621900, China
Abstract: The sub-micron ultrafine TATB particle was prepared by solvent/non-solvent cry stal technology, these factors which affect TATB particle size in the fined proc ess were reviewed relatively and the technical condition was optimized. Then the sub-micron TATB particle whose average particle size is 0.171μm and its speci fic area is over 30m 2/g was prepared.
35. Molecular and Crystal Structure of Diacetyltetranitrohexaazaisowurtzitane (DATN)
FENG Ze wang, LIU Cui ling, FANG Tao, ZHAO Xin qi
Beijing Institute of Technology, Beijing 100081, China
Abstract: Diacetyltetranitrohexaazaisowurtzitane (DATN), the intermediate in the preparation of CL 20, has been determined by single crystal X ray diffraction. It is a monoclinic, space group P2 1/n with a= 0.8545 (2) nm, b= 1.3170(3) nm, c= 1.5012(3) nm, and α=90°, β= 105.66(3)° , γ= 90° ; Z=4, D c= 1.765 g/cm 3, R= 0.0381 , R W= 0.0995 for 2857 reflections. Due to the two acetyls lying in a seven numbered ring of caged structure, the formation of DATN was considered to be a stereo selective reaction.
36. Critical Temperature of Dynamic Mechanical Performance of Some Energtic Binders at Low Temperature
QIN Ya ping, LIU Zi ru, KONG Yang hui, YIN Cui mei, ZHANG Pei
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China
Abstract: In this paper, the mechanical relaxation of some energetic binder was investigated by DMA. Base on the time temperature superposition principle of dynamic mechanical performance, the relationship curves of time shift vs logarithm frequency and constants C 1 and C 2 of WLF equation were obtained. The onset of the rubber to glass transition in the curve of time shift vs logarithm frequency was selected as failure criterion, and the critical temperature T c below which the binder will begin to rapidly lose its elastomeric properties under motor operating conditions was calculated with WLF equation. According to the free volume model and the crystallization theory, the physics significance of T c was interpreted. The relationship between the critical temperature and the glass transition temperature was investigated.
37. Crystal Structure of Four Polymorphs of Hexanitrohexaazaisowurtzitane
Ou Yuxiang Jia Huiping Chen Boren
Beijing Institute of Technology, Beijing 100081, China
Abstract: Crystal structure of four polymorphs(α, β, γ and ε) of hexanitrohexaazaisowurtzitane was measured. The crystal parameters and molecular comfiguration are given. The molecular structure of HNIW was discussed and compared with that of HMX.
38. The Study on Fining of HNS
Yuan Fengying Cao Xiong
North China Institute of Technology, Taiyuan 030051, China
Abstract: The method of fining HNS by adding surface active agent into crystal solution and ultrasonic wave processing was reported. The gained fine grains whose diameter is less than 1μm are up to moer than 55 percent.
39. Crystal Structure of Potassium Salt of 3, 5-Dinitroamine-1, 2, 4-triazole
Gao Renxiao Hu Rongzu Xu Chengdong Yu Qingsen*
Xi'an Modern Chemistry Research Institute, Xi'an 710065
*Zhejiang University, Hangzhou 310027
Abstract: The single crystal structure of potassium salt of 3, 5 dinitroamine 1, 2, 4 triazole was studied by x ray diffraction method. It is monocline system, Pa space group. Its cell parameters:a=6.597(2)A, b=5.167(2)A, c=10.427(5)A, β=95.23 0, Z=2. The absorption factor is 7.490, and the deviation factor R=0.039.
40. Application of Fuzzy Mathematics in Selection of Firing Materials
Xie Xinghua
Huainan Mining Institute 232001
Abstract: Multifactorial properties of some firing materials are evaluated. The concept of Fuzziness is used in selecting the firing materials first for engineering application. The results of comprehensive evaluation are satisfactory and in agreement with practice.
41. A Study on the Crystal Transformation of HMX with Spent Acetic Acid
Ye Ling Ye Yupeng
Beijing Institute of Technology, 100081
Abstract: To increase the economic benifit of producing HMX, the crystal transformation of α HMX with the spent acetic acid has been studied.After the crude HMX dissloves into the spent acid, the impurities will be oxided and removed.Adopting the heating and cooling technique, α HMX transforms into β HMX successfully with the acidity below 0.02% and melting point above 273℃。The optimium condition for recrystallization has been found out.
42. Study on Stability in Substituted Nitroanilines
Zhang Dechun Zhang Yanqiu
Suzhou University, Suzhou 215006
Abstract: Based on crystal structural data of substiuted nitroanilines, intramolecular hydrogen bonding geometries were studied. When involved in it, the d(Car N in amine) is shortened by Ca. 0.046A on average. The shortening of d (Car N in NO 2) and lengthening of d (Car Car) are small, but still statistically significant. The (0 N in NO 2)is intherently larger than that not involved in the same molecule. The NO 2 group is nearlyl coplanar with benzene ring while the others with an alpha C H Linkage are more or less perpendicular to it. STO 3G atomic partial charges were calculated using the experimental molecular geometrics. The 0 atom in NO 2 involved in intramolecular hydorgen bonding is always more negative than the other one which is not involved in it. All the above strongly indicates the existence of the so called Resonance Assisted Hydrogen Bond (RAHB), which well explains the extra stability for the family of the compound and is consistent with their impact sensitivity datas.
43. Crystal State of 1, 3, 5-Triamino-2, 4, 6-Trinitrobenzene (TATB) Undergoing Thermal Cycling Process.
Jie Sun1 [Institute of Chemical Materials, China Academy Engineering Physics, Mianyang, Sichuan, China], Bin Kang1 [Institute of Chemical Materials, China Academy Engineering Physics, Mianyang, Sichuan, China], Chao Xue1, 2 [1Institute of Chemical Materials, China Academy Engineering Physics, Mianyang, Sichuan, China, 2School of Materials Science and Engineering, Southwest University of Science and Technology, Mianyang, Sichuan, China], Yu Liu1 [Institute of Chemical Materials, China Academy Engineering Physics, Mianyang, Sichuan, China], Yunxia Xia1 [Institute of Chemical Materials, China Academy Engineering Physics, Mianyang, Sichuan, China], Xiaofeng Liu1 [Institute of Chemical Materials, China Academy Engineering Physics, Mianyang, Sichuan, China]
Wei Zhang[Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, China], Journal of Energetic Materials; Jul-Sep2010, Vol. 28 Issue 3, p189-201
Abstract: The present report aims to discuss the crystal state variation of 1, 3, 5-triamino-2, 4, 6-trinitrobenzene (TATB) suffering from thermal cycling process. In this study, in situ X-ray powder diffraction (XRD) was employed to determine thermal expansion and crystal fragmentation, primarily attributed to its crystal state variation. The results showed that the change of crystal volume mainly stemmed from the thermal expansion at the c axis of crystal lattice, and TATB crystal had the same thermal expansion coefficients at a and b axes. It was also demonstrated that crystal fragmentation occurred during this process, and more auto-repair happened in the [002] plane of TATB than other planes. These results will have an implication on the process of TATB-based materials.
44. Resonance-assisted hydrogen bonds in nitrobenzenes
De-Chun Zhang [Department of Chemistry, Suzhou University, Suzhou, P.R. China] ; Yan-Qui Zhang [Department of Chemistry, Suzhou University, Suzhou, P.R. China], Journal of Energetic Materials, Volume 15, Issue 2 & 3 June 1997 , pages 205 - 216
Abstract: Based on crystal structural data of 155 substituted nitrobenzenes, geometries of intramolecular hydrogen bonds were examined, which strongly suggested that the hydrogen bonds were enhanced by the resonance which exists in the conjugated system. The atomic partial charges calculated at STO-3G level and other experimental data confirmed also the phenomenon.
45. Crystal chemistry study on nitrobenzenes Part 1. Molecular conformation and packing
Yan-Qiu Zhang [Department of Chemistry, Suzhou University, Suzhou, The People's Republic of China]; De-Chun Zhang [Department of Chemistry, Suzhou University, Suzhou, The People's Republic of China], Journal of Energetic Materials, Volume 14, Issue 3 & 4 September 1996 , pages 271 - 287
Abstract: Based on 79 crystal structures of nitrobenzenes, the geometry of the benzene ring and the conformation of the nitro group were examined. The bond lengths and the endocyclic angles in the nearly planar benzene ring vary considerably, with the latter being well correlated to the electronic properties of the subtituents. Packing energy was calculated and consistent well with experimental value.
46. Studies on the Non-isothermal Crystallization Behavior of Aluminum Nanopowder-Filled Poly(3, 3-bis-azidomethyl Oxetane).
Luo, Y. and Guo, K. (2010) [School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China), Propellants, Explosives, Pyrotechnics, 35: 159–163.
Abstract: Non-isothermal crystallization of aluminum nanopowder-filled poly(3, 3-bis-azidomethyl oxetane) (PBAMO) from melt at various constant cooling rates from 1 to 10 °C min−1 was studied. Ozawa's approach was used to analyze non-isothermal crystallization kinetics. It was found that Ozawa's approach was effective at medium constant cooling rate. The crystallization activation energy derived from Kissinger's equation was 80.8 kJ mol−1. The experimental results showed that the aluminum nanopowder acted as a nucleating agent to raise the peak crystallization temperature and to accelerate the crystallization rate at higher constant cooling rates. Uniform crystals which showed one melting peak could be obtained at a constant cooling rate of 1 °C min−1.
47. Study on Crystal Structure and Thermal Decomposition Mechanism of a Novel Coordination Compound [Zn(DAT)2(H2O)4](PA)2⋅2H2O
Yan Cui1 [State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081 (P. R. China)], The 6th Department of Research Institute of Chemical Defense, Beijing 102205 (P. R. China), Tonglai Zhang2 [State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081, (P. R. China), Jianguo Zhang2 [State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081, (P. R. China)], Li Yang2 [State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081, (P. R. China)], Jin Zhang2 [State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081, (P. R. China)], Xiaochun Hu2 [State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081, (P. R. China)], Propellants, Explosives, Pyrotechnics, 33: 437–442.
Abstract: A novel coordination compound [Zn(DAT)2(H2O)4](PA)2⋅2H2O has been synthesized using 1, 5-diaminotetrazole (DAT) as ligands. It crystallizes in the monoclinic space group C2/c, with a=1.51973(19) nm, b=0.67904(9) nm, c=3.0712(4) nm, β=90.507(2)°, V=3.1692(7) nm3, Z=4, and μ=0.888 mm−1. With the intermolecular hydrogen bonds, molecules are linked together to form a three-dimensional net structure. Thermal decomposition mechanism of the title compound was predicted based on DSC, TG-DTG, and FT-IR analyses. The kinetic parameters of the first exothermic process of the title compound were studied applying the Kissinger's and Ozawa–Doyle's methods.
48. Study of the Desensitizing Effect of Different [60]Fullerene Crystals on Cyclotetramethylenetetranitramine (HMX)
Bo Jin1, Rufang Peng1, Shijin Chu1 [Southwest University of Science and Technology, Mianyang 621010 (PR China)], Yiming Huang2 [Institute of Chemical Materials, Chinese Academy of Engineering Physics, Mianyang 621900 (PR China)], Rong Wang2 [Institute of Chemical Materials, Chinese Academy of Engineering Physics, Mianyang 621900 (PR China)], Propellants, Explosives, Pyrotechnics, 33: 454–458.
Abstract: Three types of [60]fullerene crystals were obtained. The first one was the direct commercial [60]fullerene, and the other two were recrystallized from the first one in carbon bisulfide and in carbon bisulfide/petroleum ether, respectively. Scanning electron microscopy (SEM), X-ray powder diffractometry (XRD), and FT-IR spectrometry were used to study the physical characteristics of the crystals. The thermal stability of the three [60]fullerene crystals was studied by differential thermal analysis (DTA), and the effects of the three [60]fullerenes on the mechanical sensitivity and friction sensitivity of HMX were tested and analyzed. It was found that the three types of [60]fullerenes have different thermal stabilities, and the friction and impact sensitivities of HMX are reduced from 100% to 70% and to 60%, respectively when 1% [60]fullerene 3 was added in HMX.
49. Quality Evaluation of RDX Crystalline Particles by Confined Quasi-Static Compression Method
Li Ming, Huang Ming, Kang Bin, Wen Maoping, Li Hongzhen, Xu Rong [Institute of Chemical Materials (ICM), China Academy of Engineering Physics (CAEP), Mianyang 621900, China], Propellants, Explosives, Pyrotechnics, 32: 401–405.
Abstract: A confined, quasi-static uniaxial compression method, named as the compressive stiffness test (CST), is promoted to evaluate the quality of different RDX crystalline particles which are obtained from commercial and reprocessed lots. This method is based on the fact that the fragmentation or fracture behavior in the compression process could be correlated to the external/internal defects of targeted crystalline particles. The quality difference between the commonly used RDX and reprocessed RDX can be easily discriminated by compaction curves and the defined initial secant modulus can be used as a quantitative parameter to grade RDX particles. The results show that the RDX recrystallized from mixed solvents and spheroidized by treatment with solvent is of much higher quality than the commonly used RDX, and the particle size as well as external characteristics exert limited effects on the compaction curves, but the key factor is internal defects, which affect the coherence strength of RDX crystalline particles. Qualitative optical image analysis and quantitative particle apparent density measurements by liquid density gradient tubes also give consistent results with those from the CST.
50. Crystal Structure, Thermal Decomposition and Properties of Cesium 3, 5-Dihydroxy-2, 4, 6-Trinitrophenolate
Hongyan Chen, Tonglai Zhang, Jianguo Zhang, Chunchun Chen [State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081 (P. R. China], Propellants, Explosives, Pyrotechnics, 31: 285–289.
Abstract: A coordination polymer, cesium 3, 5-dihydroxy-2, 4, 6-trinitrophenolate ([Cs(DHTNP)]n), has been synthesized and its crystal structure determined. This crystal belongs to the monoclinic system with space group Pc. Each Cs+ is coordinated to 12 oxygen atoms from 8 different 3, 5-dihydroxy-2, 4, 6-trinitrophenolate (DHTNP−) anions, and each DHTNP− anion is coordinated with 8 Cs+ cations. The oxygen atoms of the phenolic hydroxyl group and from all of the nitro groups of the DHTNP− anion simultaneously bind to neighboring Cs+ ions. These DHTNP− molecular chains are interlaced, with the cesium atoms acting as knots, to create an infinite three-dimensional network structure. The molecules are linked by electrostatic interactions and weak van der Waals, forces and also display intramolecular hydrogen bonding, which all enhance the thermal stability of the title compound. The thermal decomposition was studied using DSC, TG-DTG and IR techniques. The results exhibit characteristics of a highly energetic compound that undergoes two highly exothermic decomposition reaction processes from 166 °C to 300 °C under the condition of a linear heating rate. The experimental sensitivity results indicate that [Cs(DHTNP)]n is quite sensitive to impact and friction.
51. Crystal Structure of Energetic Compound 4-Amino-1 , 2, 4-triazolium Picrate
Xiayun Xia, Wang Ping, Sun Jie, XIA Yun-xia, WANG Ping, SUN Jie (Chinese Academy of Engineering Physics, Institute of Chemical Materials, Sichuan, Mianyang, 621900)
Mao Zhihua, MAO Zhi-hua (Analytical and Testing Center, Sichuan University, Sichuan, Chengdu, 610064), Chinese Journal of Energetic Materials, 2010, 18(1):4-6
Abstract: A single crystal of energetic compound 4-amino-1, 2, 4-triazolium picrate (4-ATPA) was cultured from methanol solvent at 25℃. The compound crystallized in the orthorhombic system, is space group Pcnb with a=9.177(4), b=13.279(6), c=19.855(6) (A), V=2419.5(16)(A)~3, D_c=1.720 g•cm~(-3), Z＝8, μ(MoKα)=0.152 mm-1 and F(000)=1280. Of the 2580 total reflections, 2194 were unique(R_(int)=0.0048). The final R=0.0588 and wR=0.1370 for 2194 observed reflections with I>2σ(I). Single X-ray diffraction reveals that the structure is composed of 4-amino-1, 2, 4-triazolium cation and picric anion.
52. Non-isothermal Crystallization Behaviors of PBAMO
GUO Kai and LUO Yun-jun, Chinese Journal of Energetic Materials, 2009, 17(1):91~94
Abstract: The non-isothermal crystallization behaviors of poly(3, 3-bis-azidomethyl oxetane) (PBAMO) were studied during cooling with different constant cooling rates by using differential scanning calorimeter (DSC). Results show that the relationship of peak temperature of crystallization process and cooling rate is expressed well via exponential decay equation, and the crystallinity reaches the maximum value when cooling rate equals 2℃•min-1, while the fastest crystallization rate appears when cooling rate equals 5℃•min-1. Ozawa exponent m obtained by using Ozawa equation increases with temperature increasing and can be divided into three regions: (1) T＜14℃, m＜3; (2) T=14-18℃, m=3-4.12; (3)T＞18℃, m approaches 5. The crystallization activation energy calculated from Kissinger equation is 59.37 kJmol-1
53. Experimental Study on Crystallization of Casting TNT Explosive During Solidification by High-resolution X-ray CT
TIAN Yong, LIU Shi, ZHANG Wei-bin, DAI Bin, ZHOU Hong-ping and LUO Guan, Chinese Journal of Energetic Materials, 2009, 17(2):173~177.
Abstract: The crystallization characteristics of casting molding of TNT explosive was on-line studied by high-resolution X-ray computed tomography and the three-dimensional structure information and distribution rule were obtained. The results show that the rate of solidification is the highest at starting and slows down. TNT crystal is fine at first and subsequently columned and branch crystal is formed before solidification. The TNT branch crystal has obvious tropism characteristics. The shrink hole is mainly concentrated hole and small hole. The shrink holes intersect and become bigger during solidification and stable at last. They are much smaller at side and bottom and accordingly the density is higher. The volume shrink ratio is over 20% after solidification. The linear density difference between the bottom and the middle is about 1.5%-8% but up to 5%-18% between the surface and the center.
54. Preparation and Performance of HNS/HMX Superfine Mischcrystal
WANG Ping, LIU Yong-gang, ZHANG Juan, YU Wei-fei and XIA Yun-xia, Chinese Journal of Energetic Materials, 2009, 17(2):187~189
Abstract: Solvent/nonsolvent recrystallization method was used to prepare HNS/HMX mischcrystals in order to increase the energy output of HNS-IV, and its structure characterization and performance were studied in detail. Results show that β-HMX is surrounded by superfined HNS particles in the core. The specific surface area, impact sensitivity, friction sensitivity, and initiaiton energy of HNS-IV, superfined HNS/HMX(80/20) and superfined HNS/HMX(70/30) are as follows: 14.25 m2g-1, 9.98 m2g-1, 9.56 m2g-1； 52%, 76%, 78%; 14%, 16%, 19%; 0.49 J, 0.50 J, 0.58 J respectively.
55. NTO Crystal Growth: From Fractal to Cube-shaped Structure
XUE Qi-bin, HUANG Hui, KANG Bin, XU Rui-juan, GU Bin and XUE Chao, Chinese Journal of Energetic Materials, 2009, 17(4):381~384
Abstract: The volatile solvent crystallization of 3-nitro-1, 2, 4-triazol-5-one (NTO) on glass substrate was studied. The observed phenomena verify that the crystal morphologies change from fractal to cube-shaped structure due to the initial concentration increasing, and it can be explained with diffusion limited aggregation (DLA) theory. Besides, the fractal and cube-shaped structure NTOs were characterized by FTIR, XRD. The results show that crystal morphology change can not result in crystal structure transformation, and only its growth-oriented change.
56. Prediction of Crystal Morphology of HMX
DUAN Xiao-hui, WEI Chun-xue, PEI Chong-hua and LI Jin-shan, Chinese Journal of Energetic Materials, 2009, 17(6):655~659
Abstract: The crystal morphologies of α-and β-HMX were predicted by using attachment energy （AE） and Bravais-Friedel-Donnary-Harker （BFDH） models. The important crystal surfaces are (020), (011), 10-2), (11-1), 100) for β-HMX and (040), (220) and (111) for α -HMX. The analyses of the crystal surface structures show that (100) and (111) are greatly polar, and (020), (011), (11-1) and (220) are polar, while (10-2) and (040) are non-polar. It can be predicted that (100) and (111) are the important crystal surfaces in the proton solvents with strong polarity, and the appearance area of (020), (011), (11-1) and (220) is increased, and the (10-2) and (040) surfaces diminishes or disappeares, while the contrary cases occurs in the non-polar solvents.
57. Crystal Structure and Laser Sensitivity of Cobalt(III) Complex ［Co(NH3)4 (N3)2］ClO4
SHENG Di-lun, MA Feng-e, ZHANG Yu-feng, ZHU Ya-hong, CHEN Li-kui and YANG Bin, Chinese Journal of Energetic Materials, 2009, 17(6):694~698
Abstract: The single crystal of tetraamminediazido cobalt(III) perchlorate(DACP) was prepared，and its crystal structure was determined by a X-ray single crystal diffractometer. The results show that the crystal is triclinic belonging to space group of P-1 with crystal parameters of the unit cell dimensions: a =0.74229(9)nm，α =93.244(2)°； b=1.2127314) nm，β =100.074(2)°； c=1.8124(2)nm，γ =98.033(2)°, volume V=1.5851(3) nm3, Z =6, calculated density Dc=1.952 mg•mm-3, absorption coefficient μ=1.901 mm-1, F(000)=948. The compound is very sensitive to laser with a wavelength of 635 nm.
58. Recrystallization of 1, 3, 5-Triamino-2, 4, 6-trinitrobenzene in Ionic Liquids
MENG Zi-hui, YANG Feng-min, LI Qing-xia and ZHOU Zhi-ming, Chinese Journal of Energetic Materials, 2009, 17(6):753~754
Abstract: Recrystallization of 1, 3, 5-triamino-2, 4, 6-trinitrobenzene(TATB) in five kinds of ionic liquids, including 3-ethyl-1-methylimidazolium tetrafluoroborate, 3-butyl-1-methylimidazolium tetrafluoroborate, 3-butyl-1-methylimidazolium hexafluorophosphorus, 3-hexyl-1-methylimidazolium bromine and 3-butyl-1-methylimidazolium chloride(［Bmim］Cl) was investigated. TATB can be dissolved in ［Bmim］Cl, and the thermal stability of TATB improved after recrystalization in the ionic liquid was also investigated. The exothermic temperature of the recrystalized TATB (375℃) which is higher than that of raw TATB (363℃) indicats that the stability of recrystalized TATB is improved.
59. Recrystallization of Ammonium Perchlorate from Ethanol Using Supercritical Carbon Dioxide as Antisolvent
WEN Li-qun, ZHANG Tong-lai and QIN Qing-feng, Chinese Journal of Energetic Materials, 2010, 18(2):143~147
Abstract: The recrystallization of ammonium perchlorate (AP) was carried out using supercritical CO2 as the anti-solvent and ethanol as solvent. The volumetric expansion curves of CO2-ethanol were measured and the vapor-liquid equilibrium of CO2-ethanol system was calculated with Peng-Robinson equation. The effects of the main operation parameters on the result of the gas anti-solvent(GAS) recrystallization process were studied experimentally, such as the initial concentration of the solution, the final pressure and hold time after the pressurization. It is shown that the average grain size increases when the temperature rises. And the average grain size decreases when the initial concentration increases at 25 ℃ and by contraries at 31 ℃ and 40 ℃. Meanwhile the faster the pressure raising, the more uniform little AP grain could be produced. If the final pressure is more than 9 MPa, the increase of pressure has little effect on average size of AP particle. When the pressure is 6 MPa, the increase of hold time leads to a significant increase of the average grain size with a wide distribution. But when the final pressure is 9 MPa, there is a little change in size, only a slight change in its morphology. The effect of the intensity of liquid flow and the physical and chemical properties of the solvent itself were prevailing when compared to the effects of the other operation parameters. Finally, AP particles (60 nm, polyhedron) with narrow size distribution were obtained at 9 MPa, 25℃ and 35 kgh-1, and the phenomenon of intercrystalline fracture was found in AP particle.
60. Intragranular Defects and Shock Sensitivity of RDX/HMX
HUA Cheng, HUANG Ming, HUANG Hui, LI Jin-shan, NIE Fu-de and DAI Bin, Chinese Journal of Energetic Materials, 2010, 18(2):152~156
Abstract: The crystal internal defects of RDX/HMX were studied by optical microscopy with matching refractive(OMS), small angle scattering of X-ray(SASX), atomic force microscope(AFM), sink-fload method(SFM) and Mirco-CT. OMS and AFM results show that RDX/HMX has more defects and cracks than reduced sensitivity-RDX/reduced sensitivity-HMX. SASX results show that crystal internal defects of RDX/HMX are larger than that of RS-RDX/RS-HMX, and mirco-CT results show that RDX has larger internal defects than RS-RDX. Furthermore, shock sensitivity of RDX based PBXs and RS-RDX based PBXs were studied, and the results show that internal defects of RDX has great influence on shock sensitivity of RDX.
