Super-Rate Burning of HMX-GAP Propellants

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. 

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Figure 7-26. Effect of catalyst on super-rate burning of HMX-GAP composite propellant.

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