Thermal decomposition of neat diamylamyl phosphonate (DAAP), nitric acid-solvates of DAAP and 1.1 M DAAP/n-dodecane was studied calorimetrically in heat-wait-search mode for the first time. The neat DAAP decomposed beyond 500 K while DAAP center dot 0.7HNO(3). DAAP center dot HNO3 and DAAP center dot 2.1HNO(3) decomposed exothermally at 386, 381 and 366 K respectively, indicating the role of amount of nitric acid on decomposition. Mixture of DAAP and 8 M nitric acid decomposed at a lower temperature than the acid solvates with a larger excursion in temperature and pressure yielding hydrocarbons, CO2, CO, NOx and a reddish liquid or a black solid residue. Enthalpy of decomposition of DAAP center dot 0.7HNO(3), DAAP center dot HNO3 and DAAP center dot 2.1HNO(3) were found to be -237.7 +/- 4.8, -348.9 +/- 3.4 and -1002.1 +/- 2.6 kJ mol(-1) and the activation energy and pre-exponential factors were 127.5 +/- 1.5, 121.8 +/- 0.8 and 105.3 +/- 1.2 kJ mol(-1) and 9.0 x 10(13), 1.4 x 10(12) and 2.2 x 10(10) lit mol(-1) s(-1), respectively. Heat capacity (C-p) of acid solvates were measured and used for deriving the enthalpy change. (C) 2012 Elsevier B.V. All rights reserved.