PHYSICOCHEMICAL MEASUREMENTS ON INSENSITIVE MUNITIONS COMPOUND, N-METHYL-4-NITROANILINE (MNA) FOR ENVIRONMENTAL APPLICATIONS

摘要

Physicochemical properties such as solubility, octanol-water partition coefficient and Henry’s law constant of energetic compounds provide invaluable information for the overall understanding of environmental distribution, biotransformation, and potential treatment processes. The solubility, octanol-water partition coefficient, and Henry’s law constant were measured for N-methyl-4-nitroaniline (MNA), an insensitive munitions compound at 25, 35, and 45oC. The effect of ionic concentration on solubility, using electrolytes such as NaCl and CaCl2, was also studied. The aqueous solubility of MNA was measured by adding an excess amount of the solid compound (0.2 g) to a flask containing deionized water (100 mL). The equilibrium concentration of MNA was determined using UV spectroscopy. The octanol-water partition coefficients (log K_(ow)) values were determined directly with the shake-flask procedure. A modified gas-purging technique was used for the determination of Henry's law constant (K_H) of MNA. The data on the physico-chemical parameters were correlated using the standard van’t Hoff equation. The enthalpy and entropy of phase transfer were derived from the experimental data. Details of the experimental studies and results will be presented.