Studies on 3,3′-diamino-4,4′-azofurazan (DAAF)

Abstract

The specific heat capacity of 3,3′-diamino-4,4′-azofurazan (DAAF) was determined by a differential scanning calorimetry. In the temperature range of 253–373 K, the specific heat capacity (C p) versus T relationship can be fitted into a linear equation: C p (J g−1 K−1) = 0.0028T + 0.26456. The standard molar heat capacity is 215.53 J mol−1 K−1 at 298.15 K. According to the relationship between the specific heat capacity and thermodynamic functions, enthalpy, entropy, Gibbs free energy increments [H T–H 298.15], [S T–S 298.15] and [G T–G 298.15] of DAAF from 253 to 373 K with temperature interval of 10 K, relative to the standard temperature 298.15 K were calculated. The combustion energy of DAAF was measured by a precise IKA C5000 oxygen-bomb calorimeter to be Δc U = −(13188.43 ± 32.77) J g−1. The standard molar enthalpy of combustion at 298.15 K was determined to be Δc H m = −(2575.68 ± 6.42) kJ mol−1. The standard molar enthalpy of formation was calculated to be Δf H m = 429.98 ± 6.44 kJ mol−1 in accordance with Hess’s law. The detonation velocity and detonation pressure were calculated as 7.31 km s−1 and 23.61 GPa using the Kamlet–Jacobs equations according to the experimental enthalpy of formation.