Adiabatic self heating and isothermal heat generation rate of rocket propellant formulations containing ε-HNIW (ε-CL20) and GAP binder

摘要

Formulations based on high energy ingredients have the potential to become propellantsrnfor high velocity rockets. Seven formulations have been investigated and the main ingredientsrnare binder GAP (glycidyl azide polymer, bonded with Desmodur? N100), 42 to 47 mass-% ε-rnCL20 (ε-HNIW, Hexanitrohexazaisowurtzitane), 20 mass-% AP (ammonium perchlorate) andrnthe energetic plasticizers GAP-A, TMETN, BTTN in varying amounts. Ageing and thermal decompositionrnbehaviour are questions to be answered for such mixtures. From isothermal heatrngeneration rate, measured with a microcalorimeter of type TAM? (Thermal Activity Monitor),rnan unexpected course was found by the temperature change from 80℃ to 89℃. At 89℃ an endothermalrnpeak occurred not present at 80℃. Adiabatic self heating measured with an ARCTMrn(Accelerating rate Calorimeter) reveals a different behaviour in this series of seven samples. Onerngroup contains as plasticizer only TMETN whereas the other one has GAP-A in addition. Therndeflagration points and the courses of the adiabatic exotherms differ between these two groups ofrnformulations. The group with GAP-A shows a retardation of the adiabatic self heat rate h betweenrn160 und 175℃. The temperatures of the minima in h show an analogous correlation withrnGAP-A or TMETN content as do the times to minima in heat generation rate at 89℃. The wayrnto model adiabatic self heat rate truncated by deflagration is shown.