Impact friction

Molex no s 2 3 are physical mixts of AN 52—84, K perchlorate 0—20, DNT oil 7—12, baked cork 1—10, A1 powd 5—7 Ca carbonate 1%. They exhibited satisfactory sensitivity to impact, friction, flame initiation, and had excellent stability. Philips (Ref 4) reported on tests of Molex B and BB , manufd by the National Explosives Co. They are described as physical mixts of AN 80.77—85.06, flake A1 6.02—6.10, DNT oil 4.32—5.84, activated cork 2.55—4.47, Ca stearate 1.10—1.99 and Ca carbonate 0.83-0.95%. They were shown to be stable, to have fairly high brisance, but to be sufficiently sensitive to expl in the rifle bullet impact test. Byers (Refs 1 3) describes blasting expls similar in compn... 

The studies of Bobolev et al (Ref 70) on the transition from burning to detonation have already been described in Section VIII under Initiation by Impact Friction... 

II is via penetration of hot combustion products into the existing pores of the expl. Propagation in Region III is via convective flow between the charge surface and its confinement. This regime is claimed to be affected by confinement expansion (due to pressure), and by fragmentation of the peripheral portions of the expl column. The phenomena in Regions IV and V have already been described in Section VIII under Initiation by Impact Friction... 

If an expl is intended as a bursting charge in general purpose sheils, there would be required high brisance, high power, high detonation velocity, and low sensitivity to impact, friction and shock (TNT, PA, Comp B, Pento-lite, etc would be suitable)... 

So far as the anionic nature is concerned, if X- = trinitrophenolate (or picrate) I3 S, or xanthate, the diazonium salt detonates on impact, friction, heating or when radiation is present. 

Hexanitroethane is relatively insensitive to impact, friction or heat. It becomes sensitive when hydroxylated compounds are present. 

Trinitrophenol can only be stored safely in the form of a paste with water. Lead, mercury, copper, zinc, iron and nickel salts are sensitive to impact, friction and heat. Sodium, ammonium and amine salts give rise to explosions. When it was poured on to a cement floor, trinitrophenol formed a calcium salt that detonated when it came into contact with shoes. Trinitrophenol salts in the form of moist paste are stable. Aluminium salt is not explosive, but combusts spontaneously when in contact with water. 

Produced by action of acetylene on sodium gold thiosulfate (or other gold salts), the acetylide is explosive and readily initiated by light impact, friction or rapid heating to 83°C [1], This unstable detonator is noted for high brisance [2],... 

Copper(II) acetylide (black or brown) is much more sensitive to impact, friction or heat than copper(I) acetylide (red-brown) which is used in electric fuses or... 

Reputedly the most explosive substance known, it is very sensitive to impact, friction and heat. It is readily formed from ethanol and perchloric acid. 

Mercury fulminate, readily formed by interaction of mercury(II) nitrate, nitric acid and ethanol, is endothermic (AH°f (s) +267.7 kJ/mol, 0.94 kJ/g) and was a very widely used detonator. It may be initiated when dry by flame, heat, impact, friction or intense radiation. Contact with sulfuric acid causes explosion [1], The effects of impurities on the preparation and decomposition of the salt have been described [2],... 

Action of hydrogen peroxide or permonosulfuric acid on acetone produces this dimeric acetone peroxide, which explodes violently on impact, friction or rapid heating. 

The diammoniate (and that of the sodium salt) explodes on exposure to impact, friction or flame. 

An explosion in flour-bleaching operations was attributed to violent decomposition of the basic nitrate [1], which is an impact-, friction- and heat-sensitive explosive [2]. The instability is associated with the presence of reducant and oxidant functions in the same molecule. The previous formulation as tin(II) nitrate oxide is revised to that above. 

Know how such reactions might be initiated (e.g., heat, contamination, inadvertent mixing, impact, friction, electrical short, lightning). 

STABILITY HAZARDS - Thermal - Impact - Friction Peroxidation, polymerization, electrostatic charging ... 

Diazodinitrophenol (CgH Oj) has been used as an initiator in industrial blasting caps. It is less sensitive to impact, friction, and electrostatic energy than other primary explosives. It is orange-yellow in color and is sparingly soluble in water.11... 

Metal compounds containing both coordinated ammonia, hydrazine, hydroxylamine or similar nitrogenous donors, and coordinated or ionic perchlorate, chlorate, nitrate, nitrite, nitro, permanganate or other oxidising groups will decompose violently under various conditions of impact, friction or heat [1,2]. From tabulated data for 17 such compounds of Co and Cr, it is considered that oxygenated A-coordinated compounds, (particularly those which are oxygen balanced) cover... 

Reddy, G. O. et al Thermochim. Acta, 1983, 66, 231-244 Of the four salts with Hg2+, Pb2+, Ba2+ and 2Na+, the thermal sensitivity and impact-, friction- and static spark-sensitivities decreased in that order, as expected. These and other entries are ... 

Black powder is the oldest explosive in history, dating back to the eighth century. Its chemical composition is well-known as a mixture of potassium nitrate, sulfur, and charcoal. The mixture ratio is varied according to the purpose for which it is to be used, with the ranges kno3(0-58-0.79), (0.08-0.20), and ( (0.10-0.20). Black powder composed of particles less than 0.1 mm in diameter is used for shell burst of fireworks and fuses. The grade with diameter 0.4—1.2 mm is used for the launch of spherical shells of fireworks, while that with diameter 3-7 mm is used in stone mines. Since black powder is sensitive to sparks caused by mechanical impact, friction, and static electricity, black powder containers should be made of brass or aluminum alloys rather than iron or steel. When Cl and Ca or Mg are present as impurities, CaClj or MgClj is formed and the thermal performance of KN is reduced. Contamination with NaCl also needs to be avoided for the same reason. 

Sensitive Easily initiated to decomposition or detonation by flame, impact, friction, or spark... 

One must also keep in mind that these experiments are measuring the temperature sensitivity of a particular composition, in which the entire sample is heated to the experimental temperature. Ignition sensitivity can also be discussed in terms of the relative ease of ignition due to other types of potential stimuli, including static spark, impact, friction, and flame. 

Birth (Initiation) and Growth of Explosion in Solid and Liquid Explosives Initiated by Impact, Friction, etc. See Vol 2, p B127-L and under Detonation (and Explosion), Initiation (Birth), Growth, Spread and Propagation in Explosive Substances... 

Impact-Friction Pendulum Test. See Vol 1, p XVII and p A354, Footnote... 

Any form of mechanical action (such as impact, friction, etc) can cause a deton if the expl is sensitive to this action. Earlier discussions of the mechanical sensitivity of expls made use of an assumed special ability of expls to deton under mechanical stimulus alone. Recent work, particularly the experiments of Bowden et al [Refs 13,... 

Syllabus (1957-1958) pp 137-38 (Frank-Kamenetskii formulation) 151-62 [Session 13, entitled "Hetergeneity of the Initiation Process , includes initiation of solid expls by impact, friction, thermal effect, elastic waves by ultrasonic vibrations, electromagnetic energy and chemical influence. 

The following discussion on influence of hot spots in initiation of explosion by impact friction and heat is given in Dunkle s Syllabi (Refs 22 26) ... 

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