Experimental determination of the standard enthalpy of formation of 4H,8H-bis(furazano)[3,4-b:3′,4′-e]pyrazine and evaluation of its performance as a dispersant of solid fuels

Russian Chemical Bulletin - The energy of combustion ΔH°c of 4H,8H-bis(furazano)[3,4-b:3′,4′-e]pyrazine (BFP) was measured by calorimetry in the oxygen atmosphere and the...     

Pyrazolyltetrazoles—a High-Enthalpy Backbone for Designing High-Energy Compounds: An Experimental Study of the Enthalpy of Formation

The standard enthalpies of combustion and formation of isomeric nitropyrazolyltetrazoles have been measured by combustion calorimetry. Positional isomerism has been shown to have a significant effect on thermochemical characteristics. The contributions of some explosophore groups and moieties to the total heat content of the molecules have been determined. These contributions can be used to correctly calculate the enthalpy of formation of both known and hypothetical energy-intensive compounds.     

Kinetics of Thermal Decomposition of Solid Propellant Based on Aluminum and Ammonium Perchlorate

Kinetic regularities of the mass loss and heat and-gas release were studied in the thermal decomposition of a solid propellant composed of aluminum, ammonium perchlorate, and a polymer binder. It was shown that, under heating from 40 to 340°C under permanent vacuum conditions, propellant samples decompose without ignition, with the limiting mass loss in the decomposition being 48%. When experiments were performed in air, the propellant formulation decomposes with sharp ignition, with the inflammation temperature (270–287°C) and amount of volatiles released by this instant of time (10–16 wt %) dependent on the heating rate. The kinetic regularities of the mass loss in the decomposition of a solid propellant were described in terms of the polychromatic kinetics model that assumes that the reaction system has ensembles of particles differing in reactivity. The distribution functions of the mass fractions of the propellant by activation energies of decomposition were calculated. The heat release kinetics in the decomposition of a propellant formulation in the temperature range 153–270°C in a closed evacuated system is described by a sum of equations for two parallel reactions: 1st-order reaction with a heat effect Q₁ = 200 ± 5 kJ kg^–1 and 1st-order autocatalysis with heat effect Q₂ = 1900 ± 50 kJ kg–1. The rate constants and the activation parameters of the process were determined.