Ignition and Extinction of n‐Butyl Nitroxyethylnitramine‐Plasticized Polyethylene Glycol Propellants

Abstract

AbstractThe ignition and extinction of n‐butyl nitroxyethylnitramine (BuNENA)‐plasticized polyethylene glycol (PEG) propellants were investigated with respect to the concentration of binder and the ratio of plasticizer to polymer (pl/po). A distinctive change in the ignition delay time (tign) of the propellants was found at a low pressure of 0.03 MPa, where tign increases as the binder concentration increases from 24 % to 32 % and decreases when the pl/po ratio reaches from 1 to 6. The kinetic analysis shows that the ignition delay of BuNENA‐PEG propellants is due to a high activation energy of a condensed phase accompanied by the reduction of NO in the gas phase that plays an important role in the formation of luminous flames. Furthermore, the BuNENA‐PEG propellants with a high concentration of binder or a low ratio of pl/po were found to result in a relatively high value of the pressure deflagration limit (PDL) under which steady combustion cannot occur. With regard to combustion stability, it seems that the BuNENA‐PEG propellants producing relatively large amounts of CO and H2 are easy to extinguish and exhibit significant delay in ignition at low pressure.