فهرست مطالب h. r. pouretedal

The oxidation – reduction reaction of trinitrotoluene (TNT) with potassium permanganate solution and its decolorination rate are used as a quality control test in industry to verify the purity of TNT. The impurities such as other derivatives of TNT are due to increasing decolorination rate of potassium permanganate solution. On the other, nitrotoluene sulfonates are usually formed when sodium sulfite is added to TNT. The presence of sodium and sulfur in the TNT bulk is confirmed by using ICP technique. In this research, the kinetic of potassium permanganate reaction with pure TNT and nitrotoluene sulfonates (TNT and sodium sulfite) is studied using the absorption spectrometry in visible region and the rate constants and the reproducibility of the method are measured for determination of nitrotoluene sulfonates amounts. In the optimized concentrations of sulfuric acid (0.6 M) and potassium permanganate (0.6 mM), the results show 1.3 times increasing of reaction rate in the presence of nitrotoluene sulfonate. Introducing a simple, inexpensive and rapid method for quantifying nitrotoluene sulfonates are the advantages of the proposed method.

In this research, with evaluation of the solubility of cyclotetramethylene tetranitramine (HMX) explosive in different concentrations of water- methyl ethyl ketone (MEK) solvent, at a temperature range of 40-70 °C, the solubility and some thermodynamic parameters such as enthalpy of dissolution and mixing were calculated. Thereafter, in order to increase the capacity of the crystallization process, the effect of digestion of HMX in evaporative crystallization procedure on the morphology and polymorph conversion of crude HMX was investigated using electron microscopy, X-ray diffraction (XRD) and Raman spectroscopy. Then, two quantitative methods based on the XRD and Raman spectroscopy were developed for the determination of -HMX in  -type samples. The results showed that with the mentioned methods, -polymorph can be determined in the linear dynamic range of 0.32-5.25 wt. % in  -HMX. Also, the crystallization studies in MEK using digestion and evaporative crystallization showed complete conversion of crude HMX polymorphs to  -type, along with significant increasing in the crystallization capacity.