Accession Number : ADA322325

Title :   The Kinetics and Thermochemistry of the Thermal Decomposition of the Initiating Explosive, Tetrazene, near its Ignition Temperature (between 385 K and 400 K).

Descriptive Note : Technical rept.,

Corporate Author : DEFENCE SCIENCE AND TECHNOLOGY ORGANIZATION CANBERRA (AUSTRALIA)

Personal Author(s) : Whelan, Daniel J. ; Fitzgerald, Mark R.

PDF Url : ADA322325

Report Date : DEC 1996

Pagination or Media Count : 34

Abstract : The efficient explosive pick-up of the AMRL gasless cap composition based on boron / Pb3O4 / tetrazene and of many in-service stab and percussion- sensitive compositions based on primary explosive lead salts mixed with tetrazene arises from the explosive behaviour of tetrazene and its functioning as an energetic sensitizer. Using the thermoanalytical techniques of differential scanning calorimetry and thermogravimetry, it was established that tetrazene decomposes in a series of steps, close to its ignition temperature, ca. 140 deg C (413 K); initially, it softens, then it decomposes exothermically in a two-stage process, the first and main stage following an autocatalytic rate law of the form d(a)/dt = k2 a(1 - a). where a is the degree of reaction in this first stage, and t, the time. From an analysis of the kinetics carried out between 387.9 K and 398 K, it has been shown that the kinetics follow an Arrhenius rate dependency, leading to an activation energy (which can be related to the energetics in the bond-breaking processes) of 185.4 kJ/ mol and a preexponential factor, related to the entropy of the reaction, In A (/min), of 56.23.

Descriptors :   *THERMAL PROPERTIES, *TEMPERATURE, *THERMOCHEMISTRY, *IGNITION, *KINETICS, *DECOMPOSITION, *EXPLOSIVES INITIATORS, *TETRAZENES, EXPLOSIVES, CHEMICAL BONDS, CATALYSIS, LEAD COMPOUNDS, SALTS, AUSTRALIA, BORON, ENERGETIC PROPERTIES, EXOTHERMIC REACTIONS, PYROLYSIS, ENTROPY, CALORIMETRY, ACTIVATION ENERGY, ARRHENIUS EQUATION, THERMOGRAVIMETRIC ANALYSIS.

Subject Categories : Organic Chemistry
      Ammunition and Explosives
      Physical Chemistry
      Thermodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE