Influence of 1,4-dinitropiperazine (DNP) on the pressure index of rdx containing extruded double base propellants

Abstract

Effect of 1,4-dinitropiperazine (DNP) in bringing down the pressure index (n) in RDX - containing extruded double base propellents has been studied. Experiments have been conducted on two sets of formulations based on controls of low calorimetric value (870 cal/g) and high calorimetric value (1070 cal/g). RDX content was varied between 10 and 20% and DNP content from 2 to 6 parts per 100 parts of the base composition. DNP alone does not bring down n appreciably; however, in conjuction with Basic Lead Salicylate, a well known ballistic modifier (2 parts), it brings down the n in the 70–105 kg/cm² pressure range significantly. The effect is more pronounced in the low calorimetric value compositions and a plateau effect has been observed. Addition of dinitropiperazine does not adversely affect the thermal and chemical stability of the formulations nor their mechanical properties. The temperature sensitivity of burn rate of DNP containing formulations was reduced to 0.21% / °C as compared to that of the control having of 0.32% / °C.