L-116 A Review of the Use of HTPE in Rocket Motor Propellants

July 2005
Ian Powell (Propulsion Technology) , Michael J. Fisher (CPIA, JHU, USA)

A new family of propellants based on the hydroxyl-terminated polyether (HTPE) polymer has moved into the forefront of solid propellant technology for tactical missile rocket motors, mainly because of a reduced sensitivity to Insensitive Munitions (IM) stimuli. In a number of development efforts and technology demonstrations, described in this report, rocket motors in a range of sizes containing HTPE-based propellants have demonstrated the potential to meet the IM test criteria established by NATO and national authorities, especially when loaded into motor cases, such as filament wound graphite composites, that reduce the level of confinement of the propellant. Additionally, these propellants have exhibited properties that match or exceed the performance of comparable HTPB-based propellants, as measured by density-impulse values, in both reduced smoke and aluminized formulations. Processability, ageing characteristics, burning rate, pressure exponent and temperature sensitivity have all proven adequate to meet the requirements of most tactical motor applications. The TPEG-based propellant, developed by ATK and used in the Evolved Seasparrow Missile rocket motor, is discussed, along with other more recent development activities including several potentially lower-cost alternatives.