Application of Azido Esters as Energetic Plasticizers for LOVA Propellant Formulations

Abstract

The study of a cyclotrimethylene trinitramine‐based low vulnerable ammunition (LOVA) propellant having cellulose acetate (CA) and nitrocellulose (NC) combinations as binders is described herein. Two propellant compositions (1 and 2) were prepared by replacing the non energetic plasticizer triacetin (TA) with the novel tetraazido ester plasticizers tetraazido malonate and tetraazido glutarate, respectively, and their ballistic, mechanical, and thermal properties were studied. Both compositions 1 and 2 showed thermal stability up to 200 °C with a heat release of 1752.81 and 1774.34 J g−1, respectively. Both compositions have high impact insensitivity (h50: 39 cm), friction insensitivity up to 36 kg, and an ignition temperature greater than 250 °C. The flame temperatures of 1 and 2 are 3164 and 3243 K with linear burn rate coefficients of 0.117 and 0.122 cm s−1 MPa−1, respectively. Similar percentage elongations at three different temperatures (−20 °C, +27 °C, and +55 °C) conditions were recorded for both compositions.

Synthesis and Properties of 3‐Azido‐2,2‐bis(azidomethyl)propyl 2‐Azidoacetate: A Potential Azido Ester Plasticizer

“…Then, it could be concluded that ABAMPA is much insensitive than TAP‐Ac, which was also confirmed by the friction sensitivity (FS) results of ABAMPA (324 N) and TAP‐Ac (54 N) . Besides, the impact and friction sensitivities of ABAMPA were comparable if not less than some previously reported azido ester plasticizers, such as BAEM, BAEG and 1,5‐diazido‐3‐nitrazapentane (DIANP) ,,. Therefore, the insensitivities toward impact and friction of ABAMPA is proved experimentally.…”

“…Energetic plasticizers (EPs) are often preferred to inert plasticizers because EPs perform a dual task: retaining reasonable sensitivity, suppressing chemical reactivity, and ensuring a high thermal stability as one approaches oxygen balanced materials, creating the densest material possible. In order to increase the energy level of propellants, energetic groups such as nitro, difluoramino, nitramino, and azido groups are introduced into some molecular structures to design novel high energetic plasticizers …”

“…Compared with general organic azido compounds, energetic azido ester plasticizers provided with better lubricant effect and thermal stability, lower sensitivity and glass transition temperature . Previous work have reported the synthesis and properties of some energetic azido ester plasticizers such as bis(2‐azido‐1‐(azidomethyl)ethyl) malonate (BAEM), bis(2‐azido‐1‐(azidomethyl)ethyl) glutarate (BAEG), 1,3‐bis(azidoacetoxy)‐2,2‐bis(azidomethyl)propane (BABAMP) and triazidopentaerythrite acetate (TAP‐Ac) (Scheme ) ,,. However, the most conspicuous drawback of these azido ester plasticizers is their low level of nitrogen content, oxygen balance, density and energy.…”

Effect of inert plasticizers on mechanical, thermal, and sensitivity properties of polyurethane‐based plastic bonded explosives

“…Both inert and energetic plasticizers have involved propellant and explosive formulations to improve process parameters, mechanical properties and insensitivity properties of them . 1,2,4‐Butanetriol trinitrate, trimethylolethane trinitrate, nitroglycerin, n ‐butyl‐2‐nitratoethyl‐nitramine, triethyleneglycol dinitrate, and bis(2,2‐dinitropropyl)acetal or formal are energetic plasticizers used in especially smokeless or reduce smoke propellant formulations to compensate energy loss due to reduction or removal of metallic fuel which is responsible for primary smoke generation.…”

Plasticization of Submicron-Structured LOVA Propellants by a Linear Dinitramine

“…According to the literature [8,9], common LOVA propellants contain about ~10% nitrocellulose, ~15% plasticizers and ~75% RDX, so a similar formulation was used as starting point. To observe the influence of the various materials, other solutions were prepared by reducing the amount of RDX relative to the other compounds.…”