Thermochimica Acta, Vol.583, 59-66, 2014
Thermal decomposition behaviour of diglycolamide - Nitric acid system
The thermal decomposition behaviour of N,N,N',N'-tetraoctyldiglycolamide (TODGA) and N,N,N',N'-tetraethylhexyldiglycolamide (TEHDGA) and their solutions with n-dodecane, dihexyloctanamide and isodecanol was studied in the presence and absence of HNO3. Experiments were conducted in air ambience with closed vessel using an adiabatic calorimeter. While neat TODGA and TEHDGA were thermally stable up to similar to 600 K, they decomposed in the presence of HNO3 at similar to 400 K. The presence of n-dodecane enhanced the onset of decomposition by 20-40 K, while the dihexyloctanamide and isodecanol lowered the onsets by about 20K. From the results the rise in true adiabatic temperature (Delta T-ad) and the pressure (Delta P) as well as thermokinetic parameters such as, the enthalpy change, the activation energy and the pre exponential factor for the decomposition reaction were derived. The Delta T-ad and Delta P were seen to increase exponentially with increasing HNO3 content. (C) 2014 Elsevier B.V. All rights reserved.
Keywords:Adiabatic calorimeter;Thermal decomposition;Diglycolamide;Enthalpy;Activation energy;Spent nuclear fuel