2,4-Dinitrodiphenylamine (DNDPA) has been studied as regards its crystal st
ructure and thermal decomposition characteristics using X-ray diffraction (
XRD), simultaneous thermal analysis, ultraviolet and Visible spectroscopy,
infrared spectroscopy, hot-stage microscopy and high performance liquid chr
omatography (HPLC). The elementary cell parameters obtained from the XRD pa
ttern are a=17.002 Angstrom, b = 17.002 Angstrom, c = 20.400 Angstrom. The
crystal structure belongs to the hexagonal system with c/a ratio 1.1999. IR
spectra of 2,4-DNDPA have also been recorded and the bands assigned. Kinet
ics of thermolysis has been followed both by isothermal thermogravimetry (T
G) and HPLC. The best linearity with a correlation coefficient of 0.994 was
obtained for the two-dimensional diffusion controlled equation in TG. Acti
vation energy was found to be 83.0 kJ/mol and log A (in s(-1) = 6.0 from is
othermal TG. The rupture of the C-NH bond followed by the C-NO2 bond consti
tutes the primary step in the thermolysis and the decomposition is free-rad
ical assisted.