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Full Paper 1 DOI: 10.1002/prep.201800030 2 3 4 An Algorithm for Evaluation of Potential Hazards in 5 Research and Development of New Energetic Materials in 6 7 Terms of their Detonation and Ballistic Profiles 8 9 Sergey V. Bondarchuk*[a] and Nadezhda A. Yefimenko[b] 10 11 12 13 Abstract: In the present paper we report recommendations tionally, we have developed two utilities, which significantly 14 for safe handling with unknown explosive materials and simplify the calculation process. The proposed algorithm 15 compositions. These are based on quantum-chemical evalu- was found to be more successful in estimation of deto- 16 ations of the detonation and ballistic profiles of newly syn- nation velocity of several common explosives in compar- 17 thesized explosives and their comparison with the known ison with commercially available software EMDB, EXPLO5 18 reference compounds. The proposed methodology is rather and Cheetah 8.0. The reported results will be useful for sci- 19 simple, fast and does not require special skills. Meanwhile, it entific personnel working in the field of development and 20 allows an effective quenching of the potential risk asso- testing of explosives. 21 ciated with injuries caused by accidental explosions. Addi- 22 Keywords: chemical safety · energetic materials · detonation and ballistic properties · theoretical analysis 23 24 25 26 1 Introduction [10], in the laboratory, the most frequently injured parts of 27 human body are hands and eyes. Therefore, safety gloves 28 Current industrial, military and scientific applications require and ballistic eyewear are the most important personal pro- 29 effective high-energy density materials (HEDM), which sat- tective equipment (PPE). In the case of chemical and bio- 30 isfy the tight criteria of environmental safety and possess logical hazards, comprehensive decision logic for selection 31 high detonation performance [1–3]. Research and develop- of protective clothing was developed earlier [11]. Con- 32 ment of a new HEDM undergoes scientists of a potential versely, the choice of PPE for explosive applications still re- 33 risk of injuries; therefore, a comprehensive safety program mains to be a serious challenge for scientists. 34 for research laboratories was recently proposed [4]. These Thus, Klapo¨tke et al. [12,13] tested safety gloves using 35 risks can be associated with the both accidental explosions explosions of 1 g of lead azide in a 10 mL flask. He found 36 and unsatisfied protective measures. Often these two fac- that double-glove combination provides sufficient pro- 37 tors appear simultaneously. Such accidents happen with tection, but a wider test series must be carried out to elabo- 38 frightening regularity leading to serious disorders and often rate standardized testing protocol [13]. Murray et al. [14,15] 39 leaving workers permanently disabled. For example, an at- also performed such tests for hand, eye, face and body pro- 40 tempt to clean mechanically the valve contaminated with tection and found that in the relative vicinity between the 41 dried aryl diazonium salts resulted in injury of two workmen operator and explosive material, even small quantities of 42 [5]. The reason of this accident was in a lack of knowledge the latter (0.3 g) can lead to serious injuries. For ballistic 43 about impact sensitivity of crystalline diazoniums salts and eyewear, however, these norms already exist and according 44 the study of this phenomenon was performed only after the 45 accident. By the way, the computer prediction of impact 46 sensitivity becomes today a “double-click” procedure, since 47 a number of theoretical models are already developed and [a] Dr. S. V. Bondarchuk 48 tested [6]. Department of Chemistry and Nanomaterials Science 49 Work with small quantities of explosives, however, does Bogdan Khmelnitsky Cherkasy National University 50 not guarantee that serious injuries cannot be obtained. blvd. Shevchenko 81, 18031 Cherkasy, Ukraine *e-mail: [email protected] 51 Thus, a student-chemist lost both hands and one eye when [b] Prof. N. A. Yefimenko 52 manipulating with explosives in the laboratory [7]. Un- Department of Quality, Standardization and Project Management 53 fortunately, similar accidents are regularly described in the Bogdan Khmelnitsky Cherkasy National University 54 literature [8,9]. In contrast to bomb suits, which are neces- blvd. Shevchenko 81, 18031 Cherkasy, Ukraine 55 sary for military and some civilian applications assuming Supporting information for this article is available on the WWW 56 large-scale explosive charges (0.227–0.567 kg) being applied under https://doi.org/10.1002/prep.201800030 818 © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim Propellants Explos. Pyrotech. 2018, 43, 818–824 An Algorithm for Evaluation of Potential Hazards in Research and Development of New Energetic Materials in Terms of their DetonationBallistic and Profiles 1 them, the eyewear must be resistant to a 0.15 caliber T37 Another important parameter is the distance rD (m), 2 shaped projectile at a velocity of 640–660 ft/s [16]. which excludes the possibility of detonation transferring 3 Level of protection provided by PPE is usually estab- from the explosion on the ground surface. It is determined 4 lished on the basis of existing standards of explosives (Fig- by the formula [19]. 5 ure S1 in ESI). Detonation properties of RDX and HMX ffiffiffiffipffiffiffi p3 4 6 (chemical names are given in Table S1 in ESI) are generally rD ¼ KD Q b ð4Þ 7 applied as reference values for comparison with the pre- 8 dicted or newly synthesized explosives, which often are Herein, KD is the coefficient, which depends on the na- 9 much more powerful. Recently, we have predicted single- ture of explosive; Q is the mass of the active explosive (kg); 10 bonded crystalline phase of nitrogen, which demonstrate b is the less linear size of the passive charge (stack width). 11 the calculated detonation pressure and velocity equal to Finally, the chemical hazard of the explosive gases can 12 146.06 GPa and 15.86 km/s, respectively [17]. Similar values be quantified via the safe distance rgas (m), which excludes 13 demonstrate the other allotropes of nitrogen including mo- the action of toxic gases after explosion; this can be ex- 14 lecular crystals [18]. When handling such powerful ex- pressed by the formula [19]: 15 plosives, the safety criteria become tighter and the only pffiffiffiffi 3 16 way to estimate an appropriate level of protection is to per- rgas ¼ 160 Á Q ð1 þ 0:5uwÞ ð5Þ 17 form quantum-chemical calculations. 18 In the present paper we have focused on the safety where uw is the wind speed. In perpendicular direction to 19 norms and regulation which directly depend on the deto- the wind and during calm the term (1+0.5uw) equals to 20 nation properties of explosive materials. The purpose of this unity. 21 article is to describe a clear methodology allowing ex- Moreover, in the Ukrainian regulations on civil blasting, 22 perimentalists to perform quantum chemical calculations there are other prescribed norms which are directly related 23 from scratch. with the detonation power of explosives [20]. Thus, safe 24 work with unknown energetic materials assumes estimation 25 and comparison of three main groups of properties, which 26 2 Affected Norms and Regulations are presented in Scheme 1. The aim of the present paper is 27 to provide recommendations for estimation algorithm 28 Apart of the norms for PPE described in the previous sec- which covers the first two groups of properties before these 29 tion, there are several linear parameters, which determine will be examined experimentally according to the devel- 30 personnel safety during surface mining blasting applica- oped protocols [21]. The sensitivity parameters, however, 31 tions. These parameters directly related with the detonation also form a very important group of factors, which can be 32 properties of the explosives applied. Thus, the distance rscatt the reason of accidental explosions, but this requires a 33 (m), which is dangerous for people due to scattered of in- more specialized consideration and cannot be described in 34 dividual pieces of rock, can be expressed as the following terms of the present paper. 35 [19]: 36 sffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi 37 f d 3 Results and Discussion 1 38 rscatt ¼ 1250hexpl ð Þ 1 þ hfill a 39 3.1 Detonation Profile 40 where, h and h are the coefficients of a blast-hole filling 41 expl fill The main detonation properties of an explosive include det- with explosive and filler, respectively; f is the coefficient of 42 onation velocity (D, m/s) and pressure (P, GPa). There are rock strength according to the Protodyakonov scale; d is the 43 hole diameter; a is the distance between the holes in a row 44 or between the rows (m). 45 46 The coefficients hexpl and hfill can be expressed as in eq 2 47 and 3: 48 49 hexpl ¼ lexpl=L, ð2Þ 50 51 hfill ¼ lfill=Lstemm, ð3Þ 52 53 where, lexpl and lfill are the heights of explosive and filler; L 54 and Lstemm are the hole depth and stemming height, re- 55 spectively [19]. Scheme 1. The main elements of the safety information of ex- 56 plosives. Propellants Explos. Pyrotech. 2018, 43, 818–824 © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim www.pep.wiley-vch.de 819 Full Paper S. V. Bondarchuk, N. A. Yefimenko 1 many approaches in the literature which allow calculating quantity along with the crystal density 1 (g/cm3) becomes 2 these quantities. In this paper we do not intend to provide the only value which must be calculated (see Scheme 2). 3 a fully comprehensive review but we should highlight con- 4 tribution of Keshavarz who published about 40 individual 5 papers on different quantitative “structure-property” rela- 6 tionships (QSPR) in the field of detonation performance and 7 sensitivity of explosives.

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