Primary explosives explosive properties

Tetiyl. 2,4,6-Trinitrophenylmethylm tramine (tetryl) was used ia pressed form, mostly as a booster explosive and as a base charge ia detonators and blasting caps because of its sensitivity to initiation by primary explosives and its relatively high energy content. Properties are presented ia Table 11 (173). Batch and continuous processes for the production of tetryl have been developed. Tetryl is no longer used ia the United States and has been replaced by RDX (174-178). 

Esters of nitro alcohols with primary alcohol groups can be prepared from the nitro alcohol and an organic acid, but nitro alcohols with secondary alcohol groups can be esterified only through the use of an acid chloride or anhydride. The nitrate esters of the nitro alcohols are obtained easily by treatment with nitric acid (qv). The resulting products have explosive properties but are not used commercially. 

Tetrazene (C2H8N10O) is a pale yellow crystalline explosive generally used in ignition caps, where a small amount is added to the explosive composition to improve its sensitivity to percussion and friction. Tetrazene is not suitable for filling detonators because its compaction properties make the transition from burning to detonation very difficult. This primary explosive is stable in ambient temperatures. Its ignition temperature is lower and it is slightly more sensitive to impact than mercury fulminate. 

Mercury fulminate (C2N202Hg) is one of the most important primary explosives. It is usually found in the form of a gray powder, is sensitive to impact and friction, and is easily detonated by sparks and flames. It is desensitized by the addition of water, but is very sensitive to sunlight. It reacts with metals in moist environments. It is created by treating a solution of mercuric nitrate with alcohol in nitric acid. Its most important explosive property is that it easily detonates after initiation.10... 

Many of the nitronate salts of polynitroaliphatic compounds, particularly salts of gem-nitronitronates, exhibit properties similar to known primary explosives. Consequently, the storage of such salts is highly dangerous. Treatment of these nitronate salts with formaldehyde yields the corresponding methylol derivative via the Henry condensation. These methylol... 

Interest has focused on derivatives of mannitol hexanitrate (14) as potential explosives because although this nitrate ester is a powerful explosive it has some property characteristics of a primary explosive. Treatment of mannitol hexanitrate (14) with pyridine or ammonium carbonate " in aqueous acetone leads to a very selective denitration with the formation of mannitol-1,2,3,5,6-pentanitrate (77). Marans and co-workers synthesized the acetate (78), the propionate (79), and the phenylacetate (80) derivatives of mannitol-1,2,3,5,6-pentanitrate and all have significantly lower melting points than mannitol hexanitrate. The incorporation of such groups can also help to increase the solubility of an explosive in the melt of another explosive. 

Trinitroresorcinol (5) (styphnic acid) has also seen limited use as an explosive because of its acidic properties and the relatively high cost of resorcinol. However, the lead salt of styphnic acid has found use as a primary explosive in detonators and primers. 

The chemical properties of primary and secondary nitramines are important in relation to their use as explosives. Primary nitramines contain acidic hydrogen in the form of —N//NO2 and, consequently, in the presence of moisture, primary nitramines corrode metals and form metal salts, some of which are primary explosives. This is one reason why powerful explosives like methyinitramine (1) have not found practical use. Ethylenedinitramine (EDNA) (2) suffers from similar problems but its high brisance (VOD 8240 m/s, d = 1.66 g/cm ) and low sensitivity to impact have seen it used for some applications. 

DNBF (68) readily forms stable Meisenheimer complexes (71) with numerous oxygen and nitrogen nucleophiles and some of these are primary explosives with useful initiating properties. 

Nitrotetrazole is readily prepared from the diazotization of 5-aminotetrazole in the presence of excess sodium nitrite and is best isolated as the copper salt complex with ethylenediamine. The salts of 5-nitrotetrazole have attracted interest for their initiating properties. The mercury salt is a detonating primary explosive. The amine salts of 5-nitrotetrazole are reported to form useful eutectics with ammonium nitrate. ... 

Fuel Oil Appendix II, pp 379-407 gives details of calculations of products of detonation and tables of detonation-state properties Using a(v) equation of state Cook (Ref 1, p 284, Table 12.1) gives explosion state and other properties for some primary. and near primary explosives, which include MF, LA, HNMnt, NG, EGDN, PETN, RDX and Tetryl. 

Hydrazotetrazole. Compd investigated for use as a primary explosive. Impact sensitivity was found unsatisfactory. Some pertinent properties Impact sensitivity 32 ems, Vac Stab, 1.7 ml of gas/48 hrs/l00°C, Hot Bar Ign temp 239°C Ref Francis Taylor, NAVORD Rept 2800,... 

Handling of Explosives 406 407, Table 1. Properties of Primary Explosives... 

A major difference between primary and secondary explosives arises from the fact that primary explosives are initiated to detonate by burning whereas secondary explosives are initiated to detonate by shock waves. Therefore, the most important property of a primary explosive is its ability to undergo a fast deflagration-to-detonation transition (DDT). Thus, fast DDT is the strength of primary explosives as well as their weakness. All other parameters being equal, the faster the DDT, the better the primary explosive. At the same time,... 

In other words, the initiator, also called primary explosive, is initiated by a small energy input and its explosive output initiates the booster, which in turn, initiates the main charge that is, HE filling. The booster is sufficiently insensitive yet capable of initiation by the initiator. Booster explosives are limited in number (Tetryl and PETN) and their explosive properties are in between initiators and main charges. 

A comparison of properties of BNCP with the reported data of conventional explosives, that is, LA, LS and MF indicates that BNCP is superior to conventional primary explosives in the following respects ... 

A very important property of tetryl is its sensitiveness to initiation by a primer— hence its rapid rise in importance as an explosive for use in detonating caps, gains (boosters) etc. Martin [54] gives the following figures comparing the sensitiveness to initiation of tetryl and trinitrotoluene, under the influence of various primary explosives (Table 11). 

Other data concerning the initiating properties of lead azide, as compared with the other primary explosives, are given in Table 32. 

The explosive properties of sodium, calcium, strontium and barium azides have been investigated at the Chemisch-Technische Reichsanstalt [135]. These azides differ markedly from lead, silver and cupric azides in that they show none of the properties of primary explosives. All three may be ignited by a spark, a glowing wire or the flame of blackpowder. Calcium azide bums most rapidly and has distinctly marked explosive properties. Larger quantities of it may explode when ignited in a closed tin, while strontium and barium merely bum violently. Calcium azide detonates under the influence of a detonating cap. The sodium azide does not decompose in these conditions. The other azides show weak decomposition under the influence of a standard (No. 3) detonator. Their most important properties are tabulated below. 

According to Ficheroulle and Kovache [137] barium azide has a low sensitiveness to impact (a 2 kg weight falling from 100 cm causes 14% of explosions) but it is very sensitive to friction. It does not possess the properties of a primary explosive,... 

Trinitrotriazidobenzene (IX) is the only representative of organic azides possessing properties of primary explosives which has some prospect of practical use. Turek [159] prepared it by the action of sodium azide on sym-trichlorotrinitrobenzene (Vol. I. p. 469) and on the basis of its properties which he himself determined he suggested its use as an initiator. 

The initiating properties of the substance are characterized by the following figures (Taylor and Rinkenbach [163]) which indicate the amounts of primary explosive required to initiate different high explosives compressed under a pressure of about 14 kg/cm2. 

As early as 1883 Berthelot [75] noticed that some salts of oxalic acid (e.g. mercuric or silver oxalates) have the properties of primary explosives. 

The heavy metal salts of acetylene have the properties of primary explosives, but only cuprous acetylide was found to be satisfactory for practical use. 

T. Urbanski and Kowalski [34] have studied the explosive properties of pyridine perchlorate as well as quinoline and its nitro derivative perchlorates. Due to the introduction of a nitro group the sensitiveness to shock of the quinoline perchlorate increased, but to a smaller extent than the authors had previously observed with primary aromatic amines. The introduced nitro group markedly favoured the increase of explosive strength of the perchlorates (Table 116). 

Section 3 (1953) 2nd Supplement (1953) 32)Kirk Othmer, Vol 4 (1949), 636 -62 A.F.Wells, Crystals 33)Armour Res Foundation of IIT, "Crystallographic Properties of Primary Explosives , Summary Rept... 

T.A-Erikson R.J.Hinch, Jr, "Investigation of Crystallographic Properties of Primary Explosives , Armour Res Foundation, IIT Quarterly Rept No 1 (1958), [Ord Proj TB3-0115A, Contract DA-11-022-501-ORD-2731] 36)W.C.McCrone Assoc Inc, "The Crystallography of Explosives , Final Rept (1962) (Contract DA-11-022-ORD-4090) 37)R.C.Evans,... 

Figure 101. William H. Rinkenbach. Has published many studies on the physical, chemical, and explosive properties of pure high-explosive substances and primary explosives. Research Chemist, U. S. Bureau of Mines, 1919-1927 Assistant Chief Chemist, Picatinny Arsenal, 1927-1929 Chief Chemist, 1929—.

The same reaction occurs at lower temperatures 0.665% of a given portion of the material decomposes in 3 years at 20°, 2.43% in 1 year at 35°, 0.65% in 10 days at 50°, and 100% during 14 hours heating at 100°. The decomposition is not self-catalyzed. The product, hexanitrosobenzene, m.p. 159°, is stable, not hygroscopic, not a primary explosive, and is comparable to tetryl in its explosive properties. 

Guimont et al, Structure—Property Correlations in Primary Explosives , SRI-TPR-75-2 (1975) 56) H.L. Barreveld, The Analysis... 

C.M. Tarver et al, Structure/Property Correlations in Primary Explosives , SRI-FR-76-2, Stanford Res Inst, Menlo Park, Contract N00024-... 

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