Fast burning rocket propellants with reduced smoke

The material-based ranges of performance and properties of 3 non-aluminized rocket propellants were introduced and compared to each other. The selected formulations based on AP/HTPB; AP/PU/TMETN; and AP/HMX/GAP/TMETN have roughly the same specific impulse of 2430 Ns/kg at 70:1 expansion ratio. The burning rates in the pressure range of 10-18 MPa vary from 26-33 mm/s for the AP/HTPB propellant, 52-68 mm/s for the formulation based on AP/PU/TMETN, and 28-39 mm/s for the propellant based on AP/HMX/GAP. With 58 and 20% AP content the propellants with nitrate ester plasticizers create a much smaller secondary signature than the AP/HTPB representative contg. 86% AP. Their disadvantage, however, is the connection of high performance to a high level of energetic plasticizer. For this reason, the very fast burning propellant based on AP/PU/TMETN is endowed with a low elastic modulus and is limited to a grain configuration which is not exposed too much to the fast and turbulent airstream. The me ch. properties of the AP/HMX/GAP propellant are as good as or better than those of the AP/HTPB propellant. The 1st one exhibits the same performance and burn rates as the composite representative but produces only one fifth of HCl exhaust.