Tetryl general

Before proceeding to describe the manufacture of the nitramines, RDX and Tetryl, a few general remarks about the preparation of nitramines... 

It is an expl which is as powerful as TNT (99% by ballistic mortar), but more sensitive to impact, being comparable to Tetryl. Its 120° Vacuum Stability Test yields 8cc for a 5g sample in 8 hours, as compared with 6.5cc/5g sample in 15 hours for PETN and 3.8cc/5g sample in 48 hours for Tetryl Refs 1) Beil, not listed in General Index 2) L.F. Fieser W.H. Daudt, JACS 68, 2248-9 (1946)... 

According to Hopper, the relative sensitivity of metallic picrates depends largely upon the amts of w of crystn present. The highly hydrated forms are wry insensitive, the lower hydrates are in general more sensitive, and the anhydr forms most sensitive. The anhydr salts, with the exception of Na, Amm, Al and Fe+2, are more sensitive to impact than PA. Anhydr Cu, Zn and Cd picrates are only slightly more sensitiw, while anhydr Ni picrate is especially sensitive, lying in the sensitivity range between MF and Tetryl... 

VIII. Explosive Characteristics. Picric Acid is generally considered to be a relatively insensi tive but brisant expl. On a qualitative sensitivity scale of comparing common expls, PA would be judged to be more sensitive than TNT but appreciably less sensitive than Tetryl. Its power and brisance are also similar to those of TNT (112% TNT in the Ballistic Mortar 101% of TNT in the Trauzl Block and 107% in the plate dent test (Ref 48). In this section we will consider the steady detonation parameters. initiation characteristics and potential hazards of PA... 

RDX may be used alone in pressed charges, although for this purpose tetryl is a more general choice. For shell and bomb fillings it is too sensitive alone to initiation by impact and friction and is either desensitised with wax, or else used like PETN in admixture with TNT. RDX may also be compounded with mineral jelly and similar materials to give a useful plastic explosive. 

All the explosives used for military purposes are in general very insensitive and except in the smallest hand grenades a gaine or booster is used to ensure proper initiation. Such gaines are usually made by compressed pellets of tetryl inserted as a column into a metal tube inside the explosive charge. 

Secondary explosives (also known as high explosives) are different from primary explosives in that they cannot be detonated readily by heat or shock and are generally more powerful. Secondary explosives can be initiated to detonation only by a shock produced by the explosion of a primary explosive. Widely used secondary explosives include trinitrotoluene (TNT), tetryl, picric acid, nitrocellulose, nitroglycerine, nitroguanidine, cyclotrimethylenetrinitramine (RDX), cyclotetramethylenetetranit-... 

A sample calculation was given in Ref 29b for shock waves in air employing the general equation of state (See eq 23) for the expln products and the ideal gas adiabatic eq of state for air. Employing the method of calculation based on the hydrodynamic theory, good agreement was obtd for expls investigated (PETN Tetryl) between calculated and experimentally detd explosive properties... 

Lafitte (Ref 2), vel of deton generally increases with the diam of cartridge up to a maximum value, above which the vel remains constant. This is true for PA, RDX and for AN/Tetryl mixts contg more than 10% Tetryl, but for some other expls, such as PETN and Tetryl, the curve of deton vel vs cartridge diam increases at first, passes thru a maximum, then decreases and, after passing thtu a minimum, rises again... 

Where the maintenance of a clear channel between sprue and the slowest freezing part of a charge is impractical, cavitation is avoided by casting charges in layers, each of which is allowed to crust over before pouring the next TNT melts at 81°. It forms eutectics with RDX, Tetryl (68°), PETN (76°), and other impurities in the mix and makes these materials more soluble at higher temps. Thus, there is a general tendency for the solid content and, hence, the apparent viscosity of most castable mixts to decrease as the temp is increased. However, a reversal of the tendency toward the reduction in viscosity has been noted in Comp B when it heated above 100°... 

Sensitiveness to shock. T. Urbanski [30] has reported that PETN is exploded with a 50% probability on impact by a kinetic energy of 0.20 kgm/cm2 (in comparison with about 0.95 kgm/cm3 needed for tetryl). The data of Naofim [31] and Izzo [32] are similar. Stettbacher [33] on the other hand considered the sensitiveness to impact of PETN to be almost the same as that of tetryl. On account of its relatively high sensitiveness PETN is generally used after being desensitized ( phlegma-tized ) by adding 10% of montan (lignit) wax. This desensitization has practically no effect on the completeness of detonation. 

Nitric acid and organic and inorganic nitrates, and in general all substances which contain free nitric acid or yield nitric acid when they are treated with concentrated sulfuric acid, are analyzed by means of the nitrometer. The method depends upon the measurement of the volume of the nitric oxide which is produced when concentrated sulfuric acid acts upon the sample in the presence of mercury. It is satisfactory also for the determination of nitro group nitrogen in certain nitroamines, in nitro-guanidine and in tetryl but not in methylnitramine. It is not satisfactory in the presence of mononitro aromatic compounds or of other substances which are nitrated readily by a solution of nitric acid in concentrated sulfuric acid. 

The two reactions, hydration and dehydration, or, more exactly, the formation of nitrous oxide and of nitric acid, are more or less general reactions of the substituted nitroamines. The extent to which one or the other occurs depends largely upon the groups which are present in the molecule. Thus, tetryl on treatment with concentrated sulfuric acid forms nitric acid, and it gives up one and only one of its nitro groups in the nitrometer, but the reaction is not known by which nitrous oxide is eliminated from it. Methylnitramine, on the other hand, gives nitrous oxide readily enough but shows very little tendency to produce nitric acid. 

The shock sensitivity threshold for coarse particle size expls is generally lower than for finer particles of these expls, provided the comparison is made between coarse and fine particles at the same density. This somewhat unexpected result was first reported for Tetryl by Seely (Ref 6a). Subsequently it was observed by the writer for RDX (Ref 32), by Scott for PETN, RDX Tetryl (Ref 35), and for PETN by Dinegar et al (Ref 40)... 

Aranas, Ricardo. A Spanish general specializing in Ordnance, who died in 1932. In 1906 he introduced in Spain the modem progress ve smokeless propellants and did considerable work on their improvement. He also did some work on HE s, such as tetryl, and was the author of several publications on expls and propellants Refs l)Perez Ara( 1945),426 429 2) Vivas, Feigenspan Ladreda, vol 3 (1948), S6( footnote) 212... 

The existing database on tetryl is quite limited. Most of the information on health effects comes from case studies and reports on the health of workers employed in tetryl munitions plants during World War I and World War II. The levels of tetryl to which these workers were exposed were generally not reported. Few data exist from animal studies with tetryl. None of the data located were reliable enough to determine levels of significant exposure (LSE). Because of this, estimates of levels posing minimal risk to humans (Minimal Risk Levels, or MRLs) could not be derived. 

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