RT Journal Article ID 1949ce0b62b859ca A1 Perut, Christian T1 FUTURE CHEMICAL PROPELLANTS FOR SPACE, DEFENSE, AND COMMERCIAL APPLICATIONS JF International Journal of Energetic Materials and Chemical Propulsion JO IJEMCP YR 2007 FD 2007-03-01 VO 6 IS 2 SP 181 OP 196 AB Research and development into new solid propellants is usually granted in order to satisfy defense requirements. The energetic products most frequently mentioned in formulation studies are fillers such as ADN (ammonium dinitramide), nitramines, RDX and HMX, HNIW (hexanitro-hexaazaisowurtzitane), HNF (hydrazinium nitroformate), and binders such as GAP (glycidyl azide polymer), PGLYN (polyglycidyl nitrate) and PNMMO (polynitratomethyl-methyl oxetane). The use of GAP and HNIW brings about an increase in volumetric specific impulse of 12% compared to a current XLDB, formulated with an inert polymer and loaded with RDX. The HNIW-based propellants have been assessed successfully in 10-kg grains. They are considered to be suitable for introduction in the development of motors for tactical missiles. The longer-term studies are centred on synthesis and the use of heterocyclic molecules such as the furazanes, furoxanes, tetrazines, etc. For launcher boosters, the main objectives are cost reduction, increased performance and reliability. A first generation of propellant composition could be developed in the near future, by replacing part of the AP content with a different energetic component.
Hydrazine has been used as a monopropellant since 1958. It has the disadvantage of being extremely toxic, and this has encouraged research into new compositions. These compositions comprise an ionic aqueous solution of an oxidizer and reducer. The tested oxidizers are principally HAN, ADN and HNF. There has recently been renewed interest in the use of hydrogen peroxide for space applications. Bi-liquid motors that use methane are of particular interest.
Particularly noticeable among the compositions with long-term potential is liquid hydrogen gelled through methane crystals, for example, and "High Energy Density Materials" or HEDM. For these last products, energy is supplied principally, and sometimes exclusively, by the metastability of the molecules. This new concept is envisaged for both solid and liquid propulsion.
For many years, SNPE Matériaux Energétiques has been developing compositions for applications, which are outside the field of propulsion. Vehicle safety airbags is one of such applications, which has developed very fast since the mid-1990s. The gases needed to inflate the airbag are supplied from a gas generator that contains propellant grains. The propellant used in the airbag applications must satisfy certain specifications mainly including non-toxicity of gas, moderate combustion temperature, and excellent thermal stability. SNPE Matériaux Energétiques has used its experience with solid propellants to suggest an adapted composition for such propellants to its industrial partner Autoliv Inc. In this particular propellant composition, a monolithic grain is adopted. A continuous manufacturing process using a twin-screw has been chosen for propellant production, which is suitable for large scale production of such propellant.
PyroAlliance, a subsidiary of SNPE Matériaux Energétiques, is developing onboard energetic equipments such as micro-thrusters and actuators. A new concept of actuator, is currently being developed, which is based on a hybrid design. The oxidizer used in this design can be a liquid or gaseous mixture containing oxygen-rich chemicals. This design is less cumbersome than the classic systems based on use of pressurised vessels. PB Begell House LK https://www.dl.begellhouse.com/journals/17bbb47e377ce023,1859db4e52da6fc7,1949ce0b62b859ca.html