Initiation by friction

Tetryl is a pale yellow solid, melting at 129°C. It is moderately sensitive to initiation by friction or percussion. Tetryl is most used in the form of pressed pellets as primers for other less easily initiated explosives. 

The salt is explosive and may readily be initiated by friction, heat or contact with sulfuric acid. The molecule contains two N—Ag bonds. 

MRH Barium chlorate 5.06/83, calcium chlorate 5.61/77, potassium chlorate 6.07/76, sodium bromate 4.98/80, sodium chlorate 7.32/75, zinc chlorate 6.11/76 Dry finely divided mixtures of red (or white) phosphorus with chlorates, bromates or iodates of barium, calcium, magnesium, potassium, sodium or zinc will readily explode on initiation by friction, impact or heat. Fires have been caused by accidental contact in the pocket between the red phosphorus in the friction strip on safety-match boxes and potassium chlorate tablets. Addition of a little water to a mixture of white or red phosphorus and potassium iodate causes a violent or explosive reaction. Addition of a little of a solution of phosphorus in carbon disulfide to potassium chlorate causes an explosion when the solvent evaporates. The extreme danger of mixtures of red phosphorus (or sulfur) with chlorates was recognised in the UK some 50 years ago when unlicenced preparation of such mixtures was prohibited by Orders in Council. 

Tetryl (C7H5N508) is a pale yellow crystalline solid. It is moderately sensitive to initiation by friction and percussion and is used in the form of pressed pellets as primers for explosive compositions that are less sensitive to initiation. It is slightly more sensitive than picric acid and considerably more sensitive than TNT. In the early 1900s, tetryl was used as base charges for blasting caps but now has been replaced by PETN and RDX. During World War II, tetryl was used as a component of explosive mixtures. 

Explosive Initiation by Friction, °C Initiation by Adiabatic Compression of Air, °C... 

Initiation by Friction. See Friction Sensitivity Tests in Vol 6, p F204-L and Hot Spots ... 

Perchlorates in mixtures with reducing materials are more stable than the corresponding chlorates and are not as subject to dangers from the presence of free acids. Nevertheless, it should not be assumed that all perchlorate mixtures are safe. A perchlorate mixture can be initiated by friction, impact, or spark at energies which cannot be considered safe some of these mixtures are extremely dangerous (Ref 42)... 

Very sensitive to contact with hard objects, exploding when moist. An extremely sensitive explosive when dry, initiable by friction, impact or heating. The impure product produced by allowing ammoniacal silver oxide solution to stand seems even more sensitive, often exploding spontaneously in suspension. 

The anhydrous salt explodes on impact [1], and decomposes violently at 200°C [2]. The trihydrate is also percussion sensitive [3] though other sources suggest that in clean, grease- and oil-free equipment the anhydrous salt is shockproof [4]. A bottle of the purified anhydrous salt exploded then burnt on opening, (transition to sodium chloride and oxygen has an enthalpy of 1.2 kJ/g), presumably initiated by friction in... 

Picric acid (2,4,6-trinitrophenol) is normally sold in a damp condition, containing 10% to 15% water in this state, it is relatively safe to handle. However, dry picric acid may explode on initiation by friction, shock, or sudden heating. Moreover, picric acid forms salt on contact with metals, and heavy metal picrates are highly sensitive to detonation by friction, shock, or heat. It is possible that some older reported explosions of picric acid were initiated by detonation... 

Tetryl is moderately sensitive to initiation by friction and percussion. It is more sensitive than picric acid and TNT. 

Explosions Relation Between Hardness, Melting Point and Sensitivity. Initiation by friction and impact of PETN is studied in Ae presence of the following grits NH NOg, KHSO4, AgNOg, NaaCrgO, NaOAc, KNO3,... 

The two compounds of importance are and P4S10. The former is made on a large scale for use in strike anywhere" matches according to a formula evolved by S v ne and Cahen in France in 1898. The ignition results from the violent reaction between P4S3 and KClOj which is initiated by friction of the match against glass paper (on the side of the box) or other abrasive material. A typical formulation for the match head is ... 

Due to its extreme sensitivity, nitrogen triiodide must be stored only in wet conditions, preferably under ether [11]. It retains its sensitivity to a certain extent even under water where it can be initiated by friction [13]. 

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