Of nitrocellulose nitroglycerine

Nitropolymers composed of -O-NO2 functions and hydrocarbon structures are pyrolants that produce fuel-rich products accompanied by exothermic reaction. Typical nitropolymers are mixtures of nitrocellulose, nitroglycerin, trimethylolethane trinitrate, or triethylene glycol dinitrate, similar to the double-base propellants used in rockets and guns. Mixtures of these nitropolymers are formulated as fuel-rich pyrolants used in ducted rockets. This class of pyrolants is termed NP pyrolants. 

There exist instances where an increase in the viscosity of nitrocellulose solutions is recommended as in the product intended for manufacture of blasting gelatine, i.e. for the solution of nitrocellulose nitroglycerine. The solution must have the consistency of firm gelatine. 

In propellant chemistry, especially so in the case of nitrocellulose-containing powders, the stabilizers employed are compounds which, owing to their chemical structure, prevent the acid-catalyzed decomposition of nitrocellulose, nitroglycerine, and similar nitrate esters. 

The pro )cllant is composed of nitrocellulose, nitroglycerine, plasticizer and stabilizers. The method is used to make tubes or cigarette burning cylinders. 

Baker. F.. and Privett, G.. DM studies of nitrocellulose nitroglycerine mixtures. Polymer. 28, June. 1121-1126(1987). 

Like nitrocellulose, nitroglycerin also undergoes a slow first-order exothermic decomposition at temperatures below 140°C. As the pressure is increased, this decomposition reaction is followed by a sudden explosive reaction. Evidence suggests that the explosive reaction is autocatalyzed by the accumulation of N02. The combined results of several studies indicate that... 

The nature of the nitrocellulose used is of particular importance in explosives if freedom from exudation of free nitroglycerine during storage is to be avoided. Nitroglycerine is only a poor solvent for nitrocellulose and stability of the gel depends on continuous formation and breakdown of gelled structures. The distribution of nitrogen content and viscosity, even in the individual fibres of the nitrocellulose, is therefore of paramount importance. 

Control of exudation depends mainly on the suitable choice of the nitrocellulose used. Some lack of uniformity in this product is certainly desirable. This offers no serious difficulty, although it is necessary to ensure a constant watch on manufacturing processes to see that quality is maintained. In other gelatine explosives, particularly those containing ammonium nitrate, exudation can be induced by slow chemical reaction. The addition of alkalis, for example, can liberate ammonia which in turn can react with nitrocellulose and cause it to lose its power of binding nitroglycerine. Such effects are accelerated at high temperatures and under wet conditions and it is usual practice to test all explosives under such adverse conditions before they are put on the market. 

Clearing Test A test of the speed of solution of nitrocellulose in nitroglycerine (see p. 74). 

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-... 

Double-based propellants are a mixture of nitrocellulose and nitroglycerine. This mixture increases the pressure of the gas inside the gun barrel. Double-base propellants are used in pistols and mortars. Some disadvantages of using double-base propellants is the erosion that this mixture causes to the gun barrel due to higher burn temperatures and the presence of muzzle flash. 

Since the energy contained within double-base propellants is limited because of the limited energies of nitrocellulose (NC) and nitroglycerin (NG), the addition of ammonium perchlorate or energetic nitramine particles such as HMX and RDX increases the combustion temperature and specific impulse. Extensive experimental studies have been carried out on the combustion characteristics of composite-modified double-base (CMDB) propellants containing AP, RDX or HMX parhclesli- l and several models have been proposed to describe the burning rates of these pro-... 

Single base" smokeless powder, developed mainly in the United States, uses only nitrocellulose. "Double base" smokeless powder, developed in Europe, is a blend of nitrocellulose and nitroglycerine. "Cordite," a British development, consists of 65% NC, 30% NG, and 5% mineral jelly. The mineral jelly (a hydrocarbon material) functions as a coolant and produces substantial amounts of CO 2, CO, and H 2O gas to improve the propellant characteristics. "Triple base" smokeless powder, containing nitroguanidine as a third component with nitroglycerine and nitrocellulose is also manufactured. 

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