On the Enthalpy of Formation and Enthalpy of Sublimation of Dihydroxylammonium 5,5′‐bitetrazole‐1,1′‐dioxide (TKX‐50)

Silva, Ana L. R.; Almeida, Ana R. R. P.; Ribeiro da Silva, Maria D. M. C.; Reinhardt, Jelena und Klapötke, Thomas M. (2023): On the Enthalpy of Formation and Enthalpy of Sublimation of Dihydroxylammonium 5,5′‐bitetrazole‐1,1′‐dioxide (TKX‐50). In: Propellants, Explosives, Pyrotechnics, Vol. 48, No. 7

Abstract

The thermodynamic characterization of dihydroxylammonium 5,5′-bitetrazole-1,1′-dioxide (TKX-50) was reinvestigated. Although TKX-50 is one of the most promising new-generation energetic materials, contradictory reports are found in the literature with regard to its solid enthalpy of formation. The standard (po=105 Pa) molar enthalpy of formation of crystalline TKX-50, (175.3±1.9) kJ ⋅ mol−1, was determined experimentally based on the measured standard massic energy of combustion, determined through static-bomb combustion calorimetry. Additionally, the standard molar enthalpy of sublimation of TKX-50, at T=298.15 K, (165.0±2.4) kJ ⋅ mol−1, was derived from vapor pressure measurements determined by a Knudsen mass-loss effusion technique. Finally, different approaches were used in attempts to calculate the standard enthalpy of formation of TKX-50 in the solid state. A critical overview and assessment of the data on the enthalpy of formation of TKX-50 is also presented.

• Item Type: Journal article
• Faculties: Chemistry and Pharmacy > Department of Chemistry
• Subjects: 500 Science > 540 Chemistry
• ISSN: 0721-3115
• Language: English