Ignition by impact

Pure propargyl bromide will dccomp violently or detonate at temps as low as 220° (Ref 2). Liq propargyl bromide is easily ignited by impact from such possible sources as water hammer or accidental pressurization of the accelerated liq (Ref 3). Tests at the BuMines showed a mixt of chloropicrin and propargyl bromide to be shock sensitive (Ref 3)... 

The pure material is not ignited by impact, but it is in presence of potassium permanganate or lead(II),(IV) oxide [1], or by copper oxide or silver oxide, even under an inert gas [2],... 

Elliot and Brown [62] made extensive studies of the inflammability of mixtures of perchloric acid with oxidizable substances. Most of the mixtures of 60% perchloric acid when ignited in a confined space burned to detonation. The mixtures with 70% perchloric acid and some of them with 60% perchloric acid could be ignited by impact. Explosion was induced under action of No. 6 detonator on mixtures with 60% perchloric acid with wood meal or cotton and the rate of explosion was found to be 3000 m/sec. 

Combustible materials (filter paper, rags, etc) which have been soaked with aqueous HC104 and dried should be treated with extreme care as they might be ignited by impact, friction, or heat the condensed vapor will form explosive mixtures with ammonia or with HNOa... 

Ignition Caused by Impact. Solids and liquids can be ignited by impact. Impact tests are made by having a weight fall freely through a known distance and impacting the sample. Impact can occur, for example, if containers are accidentally dropped. The interpretation of the data from impact tests can be difficult. 

This hquid acetylenic endothermic compound j estimated as 230-270 kj/mol, 2 kJ/g) may be decomposed by mild shock, and when heated under confinement, it decomposes with explosive violence and may detonate. Addition of 20-30 wt% of toluene makes the bromide insensitive in laboratory impact and confinement tests [1] More recently, it was classed as extremely shock-sensitive [2]. It can be ignited by impact derived from the liquid-hammer elfect of accidental pressurisation of the aerated liquid, and will then undergo sustained (monopropellant) burning decomposition. Propargyl bromide, added dropwise to bromine, exploded as it neared the halogen [3]. The chloro analogue is similar, but less readily ignited [4]. 

Primers, Cap Type Articles consisting of a metal or plastics cap containing a small amount of primary explosive mixture that is readily ignited by impact. They serve as igniting elements in small arms cartridges, and in percussion primers for propelling charges. UN App. B, ICAO A2, US 173.59, lATAApp. A... 

The equation of HMTD explosion (ignited by impact) is, according to Muraour, the following [47] ... 

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