Burning rate nitrocellulose

At a concentration of 5 to 25 wt %, increased the effective kill-life of the lindane spray up to 10 times. May have been used in chlordane and BHC insecticide formulations and in melt coatings for paper and cloth. In various nitrocellulose lacquers to impart weather resistance, luster, adhesion, and decreased burning rate. These lacquers may also contain dibutyl phthalate and/or tricresyl phosphate. A typical paper lacquer may contain acetone, isobutyl acetate, ethanol, toluene and up to 20 wt % PCB-1260 (Monsanto, 1960). 

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-... 

These propellants are also called colloidal or double-base (DB) propellants and have nitrocellulose (NC) and nitroglycerine (NG) as their principal ingredients. Some ingredients may also be added in small proportions to serve as stabilizer, non-explosive plasticizer, coolant, lubricant, opacifier and burning-rate modifier or other additives to impart desirable properties to the propellants. These propellants are processed into desired shapes by two methods, that is, extrusion and casting. They find wide applications in anti-tank missiles. 

Earlier observations that nitrocellulose burns very quickly in a confined space-much more quickly than blackpowder— were confirmed. Since it is difficult to reduce the burning rate by physical methods only, e.g. by compressing the nitrocellulose to increase its density, attempts were made to slow down the rate of burning by the addition of phlegmatizing substances, such as glues, waxes, fats etc. 

Fig. 115. Rate of burning of nitrocellulose under different pressures according to Andreyev [90],...

An account of smokeless powder is, in its main outlines, an account of the various means which have been used to regulate the temperature and the rate of the burning of nitrocellulose. After the degree of nitration of the nitrocellulose, other factors which influence the character of the powder are the state of aggregation of the nitrocellulose, whether colloided or in shreds, the size and shape of the powder grains, and the nature of the materials other than nitrocellulose which enter into its composition. 

This composition is somewhat hygroscopic because it contains strontium nitrate. When moistureproof stars are manufactured with this composition using nitrocellulose paste, they can be used in practice The burning rate is adjusted by changing the ratio of magnesium to oxidizers. Potassium perchlorate decreases the ash ... 

Heat of explosion of these propellants was much the same as with nitrocellulose instead of PVN. However, the mechanical properties are different decrease of tensile strength, increase of elongation at break and of flexibility. PVN did >/. not change the burning rate, but increased the pressure exponent n V = k // ). Another disadvantage was that ... 

Gunpowder (nitrocellulose + nitroglycerine) with stabilizers such as diphenylamine and diethyldiphenylurea, burning rate modifiers and coolants such as potassium nitrate, potassium sulfate, barium nitrate, or dinitrotoluene. 

Ignition of small amounts of DADP by flame produces high flames similar to those produced by combustion of nitrocellulose. In comparison to the trimer, combustion is slower and less violent without any sound effect and producing a bit more soot. The dependence of burning rate of DADP and TATP on pressure has recently been studied by Egorshev et al. (see Fig. 10.4). The burning rate increases proportionally with pressure for both peroxides to reach about 1 cm s at atmospheric pressure for TATP and 0.2 cm per second for DADP. Diperoxide bums approximately five times slower than TATP. The flame temperature of TATP exceeds that of DADP [19]. 

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