HMX-GAP Propellants

The physicochemical properties of propellants with the compositions hmx(0-4), Ihmx(0-6), and hmx(0-8) are shown in Table 7.3. Since the energy density of HMX is higher than that of GAP, the adiabatic flame temperatures of HMX-GAP propellants increase with increasing hmx-... 

A typical super-rate burning of an HMX-GAP composite propellant is shown in Fig. 7.43. The lead catalyst is a mixture of lead citrate (LC PbCi), Pb3(C5H50y)2-x H20, and carbon black (CB). The composition of the catalyzed HMX-GAP propellant in terms of mass fractions is as follows gap(0.194), hmx(0-780), lg(0 020), and, q 0.00G). GAP is cured with 12.0% hexamethylene diisocyanate (HMDI) and then crossUnked with 3.2 % trimethylolpropane (TMP) to... 

Super-rate burning only occurs when a combinabon of LC and CB is incorporated into an HMX-GAP propellantPS] Fig. 7.44 shows that the addition of LG and/or CB to GAP binder has little or no effect on the burning rate. Likewise, no effect on burning rate is seen when these additives are incorporated into HMX pressed pellets. These experimental observations indicate that super-rate burning of HMX-GAP propellants occurs only when HMX, GAP, a lead compound, and carbon are mixed together. 

Fig. 7.45 shows a set of flame photographs of HMX-GAP propellants with and without catalysts. The luminous flame front of the non-catalyzed propellant is almost attached the burning surface at 0.5 MPa (a). When the propellant is catalyzed, the luminous flame is distended from the burning surface at the same pressure (b). Since the heat flux transferred back from the gas phase and the heat of reaction at... 

Table 7.7 Physicochemical properties of TAGN-GAP and HMX-GAP propellants composed of cap(0-80)-...

The polymeric binders used for nitramine composite propellants are similar to those used for AP composite propellants, i. e. HTPB, HTPE, and GAP. The combustion performance and the products of HMX composite propellants are shown in Figs. 4.17 and 4.18, respectively. Here, the binder mixed with the HMX particles is GAP, as in the AN-GAP propellants shown in Fig. 4.16. Though the maximum Tf and f, are obtained at (HMX) = 1.0, the maximum HMX loading is less than 0.80for practical HMX-GAP propellants, at which fp = 250 s and 7 =... 

The gas phase reaction of HMX-GAP propellants occurs with two-stage zones 22 at the first-stage reaction zone the temperature increases rapidly on and just above the burning surface. At the second-stage reaction zone the temperature increases, also rapidly, at some distance from the burning surface. In the preparation zone... 

Figure 7-28 shows a set of flame photographs of the HMX-GAP propellants with and without catalysts. The luminous flame front of the noncatalyzed propellant is... 

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