THERMAL-EXPLOSION TIMES OF NITROMETHANE, PERDEUTERONITROMETHANE, AND 6 DINITROALKANES AS A FUNCTION OF TEMPERATURE AT STATIC HIGH-PRESSURES OF 1-50 KBAR

Thermal explosion times as a function of temperature have been measured for nitromethane, perdeuteronitromethane, and six dinitroalkanes at 1, 10, and 50 kbar. For a constant thermal explosion time of 30 sec, the thermal explosion temperatures were: nitromethane (1 kbar) 354°C, (10 kbar) 278°C, and (50 kbar) 184°C; perdeuteronitromethane (10 kbar) 256°C; 1,1-dinitroethane (1 kbar) 183°C and (10 kbar) 162°C; 1,1,1-fluorodinitroethane (1 kbar) 258°C and (10 kbar) 255°C; 1,1-dinitropropane (10 kbar) 162°C; 1,1,1-fluorodinitropropane (10 kbar) 257°C; 1,2-dinitropropane (1 kbar) 225°C, (10 kbar) 172°C, and (50 kbar) 143°C; and 2,2-dinitropropane (10 kbar) 257°C and (50 kbar) 298°C. At 10 kbar and 273°C, the thermal explosion time of perdeuteronitromethane was about 10 times more than that for nitromethane. Using thermal explosion theory, for nitromethane the following Arrhenius parameters were obtained: at 1 kbar, log As (As = A/sec-1) = 40, E = 127 kcal/mole; at 10 kbar, log As = 5.3, E = 22 kcal/sec mole; at 50 kbar, log As = 6, E = 20 kcal/mole. At 50 kbar and 225°C the first-order rate constant for nitromethane decomposition is more than seven powers of ten greater than for CN bond fission. The results for the dinitroalkanes show that the presence of an α-hydrogen atom decreases the explosion temperature at constant pressure and increases the sensitivity to pressure. © 1979.