NC-NG Propellants

TMETN is a liquid at room temperature and the production process of NG-TMETN propellants is the same as that described for NG-NG propellants. The shock sensitivity of TM ETN is sufficiently lower than that of NG that no desensitizers are needed for NC-TMETN propellants. Instead of the DEP or TA used as low energy density plasticizers and stabilizers of NC-NG propellants, TMETN is mixed with TEGDN, which is a dinitrate ester and hence a relatively high energy density material. Thus, the overall energy density of double-base propellants composed of NC-TMETN is equivalent to or even higher than that of NC-NG double-base propellants. 

The burning rate of the NC-NG propellant is higher than that of the NC-TM ETN propellant in the pressure range between 0.1 MPa and 10 MPa. However, the pres-... 

Combustion tests carried out for a rocket motor demonstrate a typical T combustion instability. Double-base propellants composed of NC-NG propellants with and without a catalyst (1 % nickel powder) were burned. Detailed chemical compositions of both propellants are given in Section 6.4.6 and the burning rate characteristics are shown in Fig. 6.29. The addition of nickel is seen to have no effect on burning rate and the pressure exponent is n = 0.70 for both propellants. 

The heat of explosion of the uncatalyzed NC-NG propellant decreases rapidly when the pressure is decreased below about 4 MPa, as shown in Fig. 13.12. However, the heat of explosion of the catalyzed NC-NG propellant remains relatively unchanged, even below 2 MPa. 

Substituting the measured H xp data into Eqs. (13.32) and (13.28), one obtains an experimentally determined m value as a function of pressure. The results indicate that m of the uncatalyzed NC-NG propellant is approximately 0.35 at 0.6 MPa, gradually decreases with increasing pressure, and becomes zero at 5 MPa and above m of the catalyzed NC-NG propellant is approximately zero over the same tested pressure range. Substituting the results for m and n into Eq. (13.35), one gets... 

The combustion tests conducted for a rocket motor show that the combustion becomes unstable below 1.7 MPa and that the burning acquires a chuffing mode in the case of the uncatalyzed propellant. However, as expected, the combustion is stable even below 0.5 MPa for the nickel-catalyzed NC-NG propellant, as shown in Fig. 13.13. Propellants for which the flame temperature decreases with decreasing pressure tend to exhibit T combustion instability. 

Dibutylphthalate is used as a solv for aromatic nitrocompds, such as DNT Di-nitroethylbenzene. Silk (Ref 2) patented its use for the coating of NC NG propellants to serve as a deterrant, solvent, plasticizer 8e stabilizer. It is added during the mixing process of the propellant colloid and replaces a portion of the volatile solvent, thus reducing the possibility of the loss of vol solv. It functions in the burning of pro--pellants to cool the of combustion below... 

Aeroplex Propellants are solid rocket propellants developed and manufd by the Aerojet Engineering Corp, Azusa, Calif. They consist of a finely divided crystalline oxidizer (such as Amm or K perchlorate)dispersed in a thermosetting resin(such as styrene, methyl acrylate, etc), acting as a fuel. In addition there are binders (such as resins) and other ingredients. Aeroplex propellants differ from the usual NC or NC-NG propellants not only in physical and chemical properties, but also in their methods of manuf... 

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