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Safe Reuse of Waste Product RDXH from HMX Manufacturing Process Deng-Jr Peng,* Cheng-Ming Chang, and Yo-Yu Chang DiVision of Occupational Safety, Institute of Occupational Safety and Health, Council of Labor Affairs, ExecutiVe Yuan, No. 99, Lane 407, Hengke Road, Shijr City, Taipei, Taiwan 221, ROC
Kwan-Hua Hu Jen-Teh Junior College of Medicine, Nursing and Management, Miaoli, Taiwan 356, ROC
The manufacturing process of HMX produces high-purity products, greater than 98 wt %, of which 60 wt % belongs to β form HMX for military use and the remaining 40 wt % belongs to different types (R and γ) of HMX. In the past, the remaining products have been regarded as waste materials and were burned. After improvement of the reuse technique, the remaining 40 wt % products become a reusable high explosive by using the method of slow-cooking and solvent cleaning. This high explosive is named RDXH because its chemical, physical, and detonation properties are between those of RDX and HMX. To determine safe use of RDXH, this study utilizes thermal analysis calorimetry, explosive sensitivity test equipments, X-ray diffraction techniques, and HPLC analysis to investigate the thermal properties, reaction kinetics, energy limits of explosive sensitivity, and chemical composition of RDXH. On average, the DSC experimental results of RDXH present the exothermic onset temperature 233.22 °C, release heat 3287.94 J/g, activation energy 201.16 kJ/mol, and frequency factor 2.31 × 1017 L/s. In comparison with high explosives RDX and HMX, RDXH has the onset temperature of exothermic reaction between that of RDX and HMX, releases the least heat, and possesses the highest kinetic parameters. The explosive sensitivity test results demonstrate that RDXH belongs to a passive grade and has energy limits similar to those of RDX and HMX. Results of XRD patterns and HPLC analyses indicate that RDXH contains molecular structures of 47.32 wt % RDX and 52.67 wt % HMX. Conclusively, the reusable waste product from HMX producing process, RDXH, could be safely used and transported as a high explosive. Introduction In the past three decades, the high explosives RDX (1,3,5trinitro-1,3,5-triazacyclohexane) and HMX (octahydro-1,3,5,7tetranitro-1,3,5,7-tetrazocine) have been widely used by the military. Hundreds of investigations were conducted to understand the explosive sensitivity, and thermal and kinetic decomposition mechanisms of high energetic compounds.1-8 Recent research in explosive promotion has focused on replacing more powerful and stable nitro materials with newly developed high explosives.9-11 However, the results demonstrate that RDX and HMX could be used for the next decade due to their strong power and passive explosive sensitivity. Therefore, further study is needed to increase the safety and reuse of high explosives for safer and more economical purposes. The ideal chemical producing reaction of HMX is shown in Figure 1. Hexamine and ammonium nitrate are reactants that proceed under nitric and acetic environment to form C4N8H8O8 bond links. After two-stage aging and nitrified reaction, three types of four polymorphs of high-purity (>98.0 wt %) HMX are manufactured as R-form (stable between 337 and 429 K), β-form (stable at ambient temperature), and γ-form (stable above 429 K).12 Usually, the β-form of HMX is chosen for military purposes. The method to sieve the products after final stage of reaction obtains 60 wt % β-form of HMX. In the past, the remaining 40 wt % product was regarded as waste and burned. Now, the remaining 40 wt % product has found to be a different type of HMX. A slow-cooking (boiling for a period) method can change its chemical structure by a vaporizing and condens* To whom correspondence should be addressed. E-mail: Deng@ mail.iosh.gov.tw. Tel.: 886-2-2660-7600 ext. 299. Fax: 886-2-26607732.
ing procedure. The remainer product is vaporized by slowcooking and condensed to become a crystal product which is then dissolved in acetone solution and cleaned by acetic acid,13-15 after which it is transformed to a new crystal product named RDXH. Preliminary analysis for RDXH shows chemical and physical properties similar to those of high explosive RDX or HMX and it has a detonation velocity between RDX (8.89 km/s) and HMX (9.13 km/s). In addition, the composition of RDXH is a mixture of 47.32 wt % RDX and 52.67 wt % HMX which will be verified and quantified in the following study. According to past investigations,16-23 when a new explosive was considered for use, studies of the thermal properties, reaction kinetics, explosive sensitivities, and material structure could be conducted by using DSC (differential scanning calorimetry), explosive sensitivity test instruments, XRD (Xray diffraction) techniques, and HPLC (high-performance liquid chromatography). This study utilizes these techniques to evaluate RDXH. Hopefully, this study provides a better understanding of the inherent properties of the thermal decomposition, explosive sensitivity, and composition of RDXH. The purpose is to determine if waste products from HMX production can be safely used as a high explosive. Experiment Samples. The high explosives RDX and HMX (both with purity over 98 wt %) and reusable explosive RDXH (purity over 98 wt %) were supplied directly from the Arsenal Material Production Service which belongs to a manufacturing unit under the Ministry of National Defense, ROC. The standard RDX and HMX (both with purity over 99.0 wt %) were purchased from ChemService, Inc., and wereused to prepare the HPLC calibration curve.
10.1021/ie051065j CCC: $33.50 © 2006 American Chemical Society Published on Web 03/24/2006
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Figure 1. Ideal chemical producing reaction of HMX.
Figure 2. Thermal curves of RDX, HMX, and RDXH under heating rate of 4 °C/min.
Apparatus. DSC conducted with a Mettler Toledo DSC 822e. The explosive sensitivities test instruments was a Germany BAM Fallhammer, friction sensitivity, deflagration temperature, and spontaneous temperature test apparatus. XRD experiments were conducted with a Rigaku DMAX-B, utilizing monochromatic Cu KR radiation operated at 40 KV and 50 mA. JCPDS standard files were employed to identify the various phases present. For HPLC we used a Waters model 626 pump and a model 717 plus autosampler, associated with a Merck C18 250 × 4.60 mm column. The mobile phase used methanol/H2O ) 60%:40%, and the flow rate was 1 mL/min. The gradient program wass isocratic and the detection was obtained using a Waters 996 PDA-240 nm. Results and Discussion Thermal Analysis. To study the utilization of explosive RDXH, the DSC thermal analysis technique is used for the preliminary evaluation by using various low or high heating rates at 1-5 and 15-25 °C/min.12,24-25 In addition, to compare the thermal properties of RDXH with high explosives, RDX and HMX are chosen because of their similar abilities of heat release.26-27 Figures 2 and 3 demonstrate the thermal curves of RDX, HMX, and RDXH at chosen heating rates of 4 °C/min and 20
°C/min to observe their exothermic abilities under both low and high heating rates. Obviously, heat releases of RDX and RDXH are similar, which results in two-stage exothermic peaks at low heating rate. Although RDXH still presents two-stage exothermic peaks at high heating rate, its heat release almost overlaps with that of RDX. The thermal curve of HMX shows a single and strong exothermic peak which is significantly different from RDX and RDXH at both low and high heating rates. Thus, by observation from these thermal curves, the exothermic ability of RDXH resembles that of RDX but significantly differs from that of HMX. Table 1 further indicates the thermal and kinetic parameters such as endothermic and exothermic onset temperatures, peak temperature, maximum heat flow, integrated release heat, activation energy, and frequency factor of RDX, HMX, and RDXH at various heating rates. Compared with the thermal properties of RDX, HMX, and RDXH, onset temperature of exothermic heat release and the heat release itself are useful parameters. Figure 4 presents the differences of the onset temperatures of heat release. The upward trend of exothermic onset temperature associate with heating rate increase is presented in all three thermal curves. Conspicuously, the average exothermic onset of HMX differs from RDX and RDXH by approximately 57.64 and 49.37 °C, respectively. The exothermic onset of RDXH approaches the value of RDX for an average
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Figure 3. Thermal curves of RDX, HMX, and RDXH under heating rate of 20 °C/min.
Figure 4. Exothermic onset temperature of (a) average and (b) statistic plot of RDX, HMX, and RDXH.
difference of 8.24 °C, in which the maximum and minimum odds are 32.64 and 0.67 °C between RDX and RDXH appearing at heating rate 4 and 2 °C/min. Statistically, the average exothermic onset of RDX, RDXH, and HMX fall into the confidence interval under acceptable 5% significant error. Meanwhile, the exothermic onset temperatures of RDX and RDXH demonstrate much closer but differ from HMX significantly. The compared results show the exothermic onset temperature of RDX is more advanced than RDXH and HMX
in order. In addition, Figure 5 presents the differences of heat release. On average, the odds of heat release between RDXRDXH and HMX-RDXH are 392.82 and 837.19 J/g, respectively. RDXH releases the least heat compared to RDX and HMX. Table 1 also demonstrates the kinetic parameters Ea and A of RDX, HMX, and RDXH that are calculated via Kissinger and Ozawa methods, respectively.28-33 Interestingly, kinetic parameters of these high explosives at low heating rates 1-5
Ind. Eng. Chem. Res., Vol. 45, No. 9, 2006 2957 Table 1. Thermal and Kinetic Parameters of RDX, HMX, and RDXH under Various Heating Rates
*γ: correction coefficient for linear regression.
°C/min are all the same, but they significantly differ at high heating rates of 15-25 °C/min and whole heating rates 1-25 °C/min. The determined Ea of RDXH is higher than HMX and RDX in order and the differences between RDXH-RDX and RDXH-HMX are 23.51 and 9.60 kJ/mol, respectively, by using the Kissinger method. Almost the same odds, 22.41 and 8.52 kJ/mol, are calculated by the Ozawa method. Regardless of the method used to calculate the kinetic parameters, reusable
explosive RDXH possesses the highest value and comparatively less odds to HMX in reaction kinetics. Explosive Sensitivity Tests. The explosive impact sensitivity of RDXH is tested by using the Fallhammer test apparatus. The test starts from position energy 5 kg and 20 cm to higher position energy with a result of six tests. If an impact phenomenon occurred among the six tests,the next lower position energy is chosen and the test is then conducted again. Otherwise, the
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Figure 5. Heat release of (a) average and (b) statistic plot of RDX, HMX, and RDXH. Table 2. Test Results of Explosive Impact Sensitivity of RDXH weight of drop (kg) 5
1
a
height (cm) 60 50 40 30 20 15 50 40 30 20 10
Table 3. Test Results of Explosive Friction Sensitivity of RDXH
explosion phenomenaa
1 1 0 0
0 0
0 0
0 0
0 0
suspend hammer no.
loading position (I-VI)
loading 0.5-36 kgw
9 9 9 9 8 8 8 9 8 7 7
VI V IV III VI V IV I III VI V
36.0 32.4 28.8 25.2 24.0 21.6 19.2 18.0 16.8 16.0 14.4
0 0
0 ) none and fume, 1 ) noise, 2 ) spark.
a
explosion phenomenaa 1 1 1 1 0 0 0 0 0 0 0
1 0 1 1 0 0 0
1 0 1 0
1 0
0
0
0 ) none and fume, 1 ) noise. 2 ) spark, 3 ) smog.
position energy is increased and the test is continued until six tests are completed with no impact phenomenon. The lowest impact energy is then determined via eq 1. The final test results are presented in Table 2.
by using eq 2. The test results are presented in Table 3.
Lowest impact energy ) m × g × h ) 5 kg × 9.81 (m/sec2) × 0.15 m ) 7.36 Joule (1)
In Table 4, deflagration temperature of RDXH is determined by using the liner extrapolation method with five experimental data obtained from the test apparatus. The test sample is put in a furnace and kept at an isothermal temperature. The experimental procedure is repeated at various test temperatures until the acceptable data are obtained.
The explosive fraction sensitivity test begins from the highest load (36 kgw) to the lowest load that could cause the sample to react. The explosive fraction sensitivity of RDXH is calculated
Lowest friction loading ) m × g ) 16.0 kg × 9.81 (m/sec2) ) 156.96 Newton (2)
Ind. Eng. Chem. Res., Vol. 45, No. 9, 2006 2959 Table 4. Test Results of Deflagration Temperature of RDXH test no.
test temp. (°C)
reaction time (sec)
1 2 3 4 5
256 261 270 282 292
13.2 10.5 7.8 6.2 4.9
noise
explosion phenomena spark smog
none
× × × × ×
Table 5. Compared Explosive Sensitivity Test Results of RDXH with High Explosives RDX and HMX sample explosive sensitivity lowest impact energy lowest friction loading deflagration temperature spontaneous temperature a
RDXH (dry)
HMX (dry)
RDX (dry)
7.36 J 156.96 Na 290.1 °C 228.0 °C
8.0 Ja 80.0 N 328.0 °Ca 279.0 °Ca
5.0 J 120.0 N 280.0 °C 210.0 °C
The best demonstrated explosive sensitivity. Figure 7. XRD patterns of (a) RDXH, and high explosives (b) RDX and (c) HMX.
Figure 6. Spontaneous temperature test curve of RDXH.
The test results to determine the spontaneous temperature of RDXH are presented in Figure 6. The test sample is placed into a furnace and a thermocouple is used to measure the temperature. The sample is then heated in the furnace at a rate of 5 °C/min until heat is released from a RDXH pyrolysis reaction. The spontaneous temperature can then be determined. It should be noted that the test result of explosive sensitivity is a nonabsolute value but a limited energy which can be used as one of the criteria to quantify the passive grade of explosive. Thus, the quantitative results determine the sensitivity for safety of use and transport consideration.34 The aforementioned test results of explosive sensitivity are used to determin if RDXH could be safely used as a high explosive. The test results are compared with those from high explosives RDX and HMX as presented in Table 5. A better impact and fraction test results of explosive sensitivity was demonstrated by RDXH than RDX. RDXH has similar thermal and kinetic parameters but more passive explosive sensitivity than RDX. In conclusion, reusable explosive RDXH can be classified under the same passive grade with RDX and HMX as an inactive high explosive according to the classification of UN Committee of Experts on the Transport of Dangerous Goods.34 Based on the results of thermal analysis and explosive sensitivity, RDXH could be safety used as a high explosive as RDX and HMX so far.
Figure 8. HPLC calibration curves of (a) RDX and (b) HMX.
X-ray Diffraction. To understand the molecular structure of RDXH, XRD is performed to study the RDXH, RDX, and HMX patterns, as presented in Figure 7. Note that some peaks in the XRD patterns of RDXH disappear at high X-ray energy. For instance, 40 kV and 100 mA X-ray result in an unstable RDXH structure. This phenomenon is confirmed several times, and it is ameliorated after lowering the XRD energy to 40 kV and 50 mA. The RDXH experimental result shows that this compound does not have a simple structure. Most XRD patterns of RDXH fail to exactly fit the intensity of RDX and HMX patterns. This result certainly demonstrates that RDXH contains both RDX
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Figure 9. Selected HPLC experimental curve of RDXH (Run 3 in Table 7). Table 6. Basic Calibration Data of RDX and HMX by Using HPLC standard
concn (µg/mL)
peak area (run 1)
peak area (run 2)
peak area (run 3)
peak area (mean)
SD
CV (%)
RDX RDX RDX HMX HMX HMX
396 792 990 396 792 990
9635590 19411934 22982826 10680839 22777676 28368458
10059607 19338574 23444779 11071734 22809895 28587376
9731485 19381513 23662461 11056783 22766595 28637718
9808894 19377340 23363355 10936452 22784722 28531184
222355 36858 347057 221494 22493 143155
2.27 0.19 1.49 2.03 0.10 0.50
Table 7. HPLC Experimental Data of RDXH sample
concn (mg/mL)
peak area (run 1)
peak area (run 2)
peak area (run 3)
peak area (mean)
SD
CV (%)
composition (µg/mL)
RDXH (RDX) RDXH (HMX)
1.02 1.02
12202332 15594077
12232759 15582417
12235928 15578592
12223673 15585029
18550 8066
0.15 0.05
496 552
(orthorhombic phase) and HMX (monoclinic phase) structures that could be corroborated by comparing the XRD pattern angles of RDX and HMX. Thus, this study proposes that RDXH possesses both C3H6N6O6 (RDX) and C4H8N8O8 (HMX) chemical formulas in one explosive unit. HPLC Chromatography. Further evidence to prove RDXH contains both RDX and HMX structures is sought by using chromatographic instrument HPLC. The purity of standards of RDX and HMX used are greater than 99.0 wt %. Acetonitrile is used as a solvent to prepare three different standard concentrations, 396, 792, and 990 µg/mL, for plotting HPLC calibration curves. Each concentration test is repeated three times under the same conditions. The basic calibration data and curves of standard RDX and HMX as shown in Table 6 and Figure 8 are prepared to quantify the RDXH components. For sample preparation 5.10 mg of RDXH is accurately weighed into a volumetric flask and acetonitrile is added to make up the volume to 5.0 mL. A 10 µL aliquot of the RDXH solution is injected to HPLC. The HPLC experiment of RDXH is repeated three times to confirm the reappearance. As shown in Figure 9, there are two peaks for pure material ,which are verified to belong to HMX and RDX by using HPLC analysis presented in Table 7. In the HPLC composition analysis of RDXH, the peak area of HMX appears first at retention time 3.051 min and the peak area of RDX appears later at 3.944 min. In addition, the percentage of peak area of HMX belongs to 56.01% and the other part of RDX is 43.99% as shown in Figure 9. This result indicates that RDXH contains both HMX and RDX. Continuously, the HPLC analysis repeats three times to verity the reappearance and quantification of contained composition in
RDXH. In summary, the average HPLC experimental results show that RDXH contains 47.32 wt % of RDX and 52.67 wt % of HMX. This result also proves the XRD observation which indicates that RDXH contains both RDX and HMX structures. Conclusions Summarizing the experimental results of thermal analysis, the reusable waste product from HMX production process, RDXH, demonstrates the thermal properties and kinetic parameters similar to those of high explosives RDX and HMX. In addition, the test results of explosive sensitivity indicate the energy limits for RDXH could be safely used or transported as a passive high explosive, similarly to RDX or HMX. The analyzed results of XRD pattern and HPLC experiments show the RDXH contains both RDX and HMX molecular structures and chemical composition (47.32 wt % C3H6N6O6 and 52.67 wt %C4H8N8O8). Therefore, this study concludes that the RDXH can be safely used as a high explosive. Interestingly, the friction sensitivity of RDXH surprisingly demonstrates higher value than, but not between, that of pure RDX and HMX. This result has been verified four times. Thus, despite this study determining the sensitive energy limits of RDXH for safe use purpose, the further experiments of explosive sensitivity of RDXH should be conducted for statistic analysis to realize the potential interesting information and the aforementioned surprise.35-38 In addition, further thorough investigation could also be conducted associated with the aforementioned results. Kinetic decomposition paths and advanced chromatog-
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raphy analysis (GC mass-FTIR) for analyzing reacting products of RDXH and so on, could be considered for study in the future. Acknowledgment We appreciate the financial support provided by The Institute of Occupational Safety and Health, Council of Labor Affairs, Executive Yuan, under grant No. IOSH93-S302, and 203Rd Arsenal Material Production Service provided valuable help in this study. Literature Cited (1) Yoshida, T. Safety of ReactiVe Chemicals; Elsevier: Amsterdam, The Netherlands, 1987. (2) Yoshida, T.; Wada, Y.; Foster, N. Safety of ReactiVe Chemicals and Pyrotechnics; Elsevier: Amsterdam, The Netherlands, 1995. (3) Tarver, C. M.; Chidester S. K.; Nichols, A. L, III. Critical conditions for impact- and shock-induced hot spots in solid explosives. J. Phys. Chem. 1996, 100, 5794. (4) Berghout, H. L.; Son, S. F.; Skidmore, C. B.; Idar, D. J.; Asay, B. W. Combustion of damaged PBX 9501 explosive. Thermochim. Acta 2002, 384, 261. (5) Kimura J.; Kubota, N. Thermal decomposition process of HMX. Propellants Explos. 1980, 5, 1. (6) Hussain, G.; Rees, G. J. Thermal decomposition of HMX and mixtures. Propellants, Explos., Pyrotech. 1995, 20, 74. (7) Kim, E. S.; Lee, H. S.; Mallery, C. F.; Thynell, S. T. Thermal decomposition studies of energetic materials using confined rapid Thermolysis/FTIR spectroscopy. Combust. Flame 1997, 110, 239. (8) Hobbs, M. L. HMX Decomposition model to characterize thermal damage. Thermochim. Acta 2002, 384, 291. (9) Qstmark, H.; Bergman, H.; Ekvall, K.; Langlet, A. A study of the sensitivity and decomposition of 1,3,5-trinitro-2-oxo-1,3,5-triazacyclohexane. Thermochim. Acta 1995, 206, 201. (10) Hsieh, C. F.; Liu, T. K.; Yuan, L. Y.; Hwang, T. S.; Yu, F. E.; Chen, D. M. A comparative study of combustion phenomena of double base and RDX-composite modified double base propellants. J. Explos. Propellants R.O.C. 2001, 17, 67. (11) Lin, Y. H.; Chao, H. M.; Yeh, T. F.; Yang, G. K. The prospect of insensitive munitions and energetic materials for 21st century. J. Explos. Propellants R.O.C. 2002, 18, 17. (12) Kim, E. S.; Lee, H. S.; Mallery, C. F.; Thynell, S. T. Thermal decomposition studies of energetic materials using confined rapid thermolysis/FTIR spectroscopy. Combust. Flame 1997, 110, 239. (13) Burch, D.; Johnson, M.; Sims, K. Valued added products from reclamation of military munitions. Waste Manage. 1997, 17, 159. (14) Lyman, J. L.; Liau, Y.-C.; Brand, H. V. Thermochemical functions for gas-phase, 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane (HMX), its condensed phases, and its larger reaction products. Combust. Flame 2002, 130, 185. (15) van der Heijden, A. E. D. M.; Bouma, R. H. B. Crystallization and characterization of RDX, HMX and CL-20. Cryst. Growth Des. 2004, 4, 999. (16) Johnson, M. A.; Truong, T. N. Importance of polarization in simulations of condensed phase energetic materials. J. Phys. Chem. B 1999, 103, 9392. (17) Agrawal, J. P.; Surve, R. N.; Sonawane, S. H. Some aromatic nitrate esters: synthesis, structural aspects, thermal and explosive properties. J. Hazard. Mater. 2000, A77, 11. (18) Groom, C. A.; Beaudet, S.; Halasz, A.; Paquet, L.; Hawari, J. Detection of the cyclic nitramine explosives hexahydro-1,3,5-trinitro-1,3,5-
triazine (RDX) and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazine (HMX) and their degradation products in soil environments. J. Chromatogr. A 2001, 909, 53. (19) Hammerl, A.; Klapotke, T. M.; Noth, H.; Warchhold, M. [N2H5]+2[N4C-NdN-CH4]2-: A new high-nitrogen high-energetic material. Inorg. Chem. 2001, 40, 3570. (20) Mehilal, R. B. S.; Sikder, A. K.; Agrawal, J. P. Synthesis and characterization of 4-picrylamino-2,6-dinitrotoluene (PADNT): a new insensitive explosive. J. Hazard. Mater. 2001, A84, 117. (21) Mehilal, R. B. S.; Sikder, A. K.; Pawar, S.; Sikder, N. Synthesis, characterization, thermal and explosive properties of 4,6-dinitrobenzofuroxan salts. J. Hazard. Mater. 2002, A90, 221. (22) Sikder, N.; Bulakh, N. R.; Sikder, A. K.; Sarwade, D. B. Synthesis, characterization and thermal studies of 2-oxo-1,3,5-trinitro-1,3,5-triazacyclohexane (Keto-RDX or K-6). J. Hazard. Mater. 2003, A96, 109. (23) Talawar, M. B.; Sivabalan, R.; Senthilkumar, N.; Prabhu, G.; Asthana, S. N. Synthesis, characterization and thermal studies on furazanand tetrazine-based high energy materials. J. Hazard. Mater. 2004, A113, 11. (24) Mintz, K. J.; Jones, D. E. G. Thermal analysis of monomethylammonium nitrate. Thermochim. Acta 1996, 284, 57. (25) Jones, D. E. G.; Lightfoot, P. D.; Fouchard, R. C.; Kwok, Q.; Turcotte, A.-M.; Ridley, W. Hazard characterization of KDNBF using a variety of different techniques. Thermochim. Acta 2002, 384, 57. (26) Peng, D. J.; Chang, C. M.; Chiu, M. Thermal reactive hazards of HMX with contaminants. J. Hazard. Mater. 2004, A114, 1. (27) Peng, D. J.; Chang, C. M.; Chiu, M. Thermal analysis of RDX with contaminants. J. Therm. Anal. Calorim. 2006, 83, 657. (28) Kissinger, H. E. Reaction kinetics in differential thermal analysis. Anal. Chem. 1957, 29, 1703. (29) Ozawa, T. Kinetic analysis of derivative curves in thermal analysis. J. Therm. Anal. 1970, 2, 301. (30) Rao, T. L. S.; Lad, K. N.; Pratap, A. Study of nonisothermal crystallization of amorphous Cu50Ti50 alloy. J. Therm. Anal. Calorim. 2004, 78, 769. (31) Lopez-Fonseca, R.; Landa, I.; Gutierrez-Ortiz, M. A.; GonzalezVelasco, J. R. Non-isothermal analysis of the kinetics of the combustion of carbonaceous materials. J. Therm. Anal. Calorim. 2005, 80, 65. (32) Rocco, J. A. F. F.; Lima, J. E. S.; Frutuoso, A. G.; Iha, K.; Ionashiro, M.; Matos, J. R.; Suarez-Iha, M. E. V. Thermal degradation of a composite solid propellant examined by DSC: Kinetic study. J. Therm. Anal. Calorim. 2004, 75, 551. (33) Bina, C. K.; Kannan, K. G.; Ninan, K. N. DSC study on the effect of isocyanates and catalysts on the HTPB cure reaction. J. Therm. Anal. Calorim. 2004, 78, 753. (34) TOD (Transport of Dangerous Goods). Transport of Dangerous Goods Tests and Criteria; United Nations: New York, 1990. (35) Wharton, R. K.; Rapley, R. J.; Harding, J. A. The Mechanical Sensitiveness of Titanium/Blackpowder Pyrotechnic Compositions. Propellants, Explos., Pyrotech. 1993, 18, 25. (36) Rice, B. M.; Hare, J. J. A quantum mechanical investigation of the relation between impact sensitivity and the charge distribution in energetic molecules. J. Phys. Chem. A 2002, 106, 1770. (37) Shuji, Y.; Tonokura, K.; Koshi, M. Energy transfer rates and impact sensitivities of crystalline explosives. Combust. Flame 2003, 132, 240. (38) Keshavarz, M. H.; Pouretedal, H. R. Simple empirical method for prediction of impact sensitivity of selected class of explosives. J. Hazard. Mater. 2005, A124, 27.
ReceiVed for reView September 22, 2005 ReVised manuscript receiVed February 15, 2006 Accepted February 28, 2006 IE051065J
