Synthesis and Characterization of Azido Esters as Green Energetic Plasticizers

Abstract

Three azido-esters based green energetic plasticizers were synthesized from their chlorides including DEG-BAA (diethyleneglycol bis(azidoacetate)), DPGBAA (dipropyleneglycol bis(azidoacetate)) and HETTAA (hexanetriol tris (azidoacetate)). The syntheses were carried out in a twostep process: the first step was esterification of glycol or triol using chloroacetyl chloride, and the second step was substitution of chloracetate with sodium azide that yields corresponding azido derivatives. The parameters of synthesis such as molar ratio of hydroxyl and acyl groups, and amount and type of solvent (dimethyl sulfoxide and dimethyl formamide) were optimized to achieve maximal conversion and purity of the products. The obtained products were characterized by elemental analysis, nuclear mag-netic resonance (NMR), and infrared vibrational spectroscopy (IR). Thermal and rheological properties were determined using DSC and Modular Compact Rheometer. Condensed phase heat of formation and several properties important for high-energy materials were predicted from quantum chemical calculations using CBS-4M method. Detonation and combustion performance of energetic compounds were calculated with the thermochemical computer code EXPLO5V06.05. using the predicted heats of formation and experimentally determined densities as input. The energetic and physical properties of the synthesized compounds were compared to the literature data for common plasticizers.

Recent advances in the synthesis and properties of energetic plasticizers

“…Sheibani and Nešić et al synthesized a series of azido-ester based EPs with different chain types from different alcohols, including glyceryl tris(azidoacetate) ( GTAA ) and triethyleneglycol bis(azidoacetate) ( TEGBAA ), 50 and dipropy leneglycol bis(azidoacetate) ( DPGBAA ) and hexanetriol tris (azidoacetate) ( HETTAA ) (Scheme 18). 51 Among the prepared compounds, multibranched GTAA and HETTAA exhibit higher glass transition temperatures (−56 °C, −56 °C) and lower thermal decomposition temperatures (246 °C, 243 °C) than those ( T g : −62 °C, −63 °C, and T d : 257 °C, 254 °C) of TEGBAA and DPGBAA . Among them, GTAA has the highest density (1.42 g cm −3 ) and DPGBAA has the lowest density (0.95 g cm −3 ).…”

Tris(3-nitropentane-2,4-dionato-κ2 O,O′) Complexes as a New Type of Highly Energetic Materials: Theoretical and Experimental Considerations

“…The application of high-energy materials (explosives, fuels, and propellants) in the industry is largely limited by their sensitivities toward detonation [1][2][3][4][5][6]. Multiple factors affect the sensitivity of high-energy materials towards detonation, like free space in the crystal lattice, the heat of detonation, positive values of electrostatic potential above the central regions of the molecular surface, and the presence of hydrogen bonds [7][8][9][10][11][12].…”

How Do Small Differences in Geometries Affect Electrostatic Potentials of High-Energy Molecules? Critical News from Critical Points

“…The development of new classes of high-energy materials (HEM) with improved detonation performance and moderate sensitivity towards detonation is the ultimate goal of many theoretical and experimental studies [1][2][3][4][5][6]. Properties of new HEM compounds could be predicted by analysis of crystalline and molecular factors that play role in the initiation of the detonation process [7].…”