Inverse Microemulsion Preparation Of Nano Rdx

In this paper, the preparation of nano-RDX in reverse microemulsion has been researched. The paper has studied how the factors such as the mass ratio of Span80and Tween20, the mass ratio of composite surfactant and co-surfactant, oils, different kinds of co-surfactants and temperature affect the phase area of the reverse microemulsion, as well as the changes in conductivity and O-H stretching vibration peak by different water content. The researches have showed that microemulsion has maximum phase area when the experiment temperature is40℃, the mass ratio of Span80and Tween20is7/3, the mass ratio of composite surfactant and n-hexanol is7/3. Furthermore, with the increase of water content, the conductivity of the reverse microemulsion tend to increase, and the O-H stretching vibration absorption strength is obviously enhanced, the absorption wave number move to the lower wave-number direction.Under the condition of the optimum ratio of microemulsion constituents, the factors influencing the particle size of RDX such as the mole ratio of water and surfactant, the concentration of RDX solution, different kinds of RDX solvent have been researched. Through analysis of infrared spectrogram, thermal decomposition characteristic, impact sensitivity and friction sensitivity, the characterization of raw RDX and sub-micron RDX have also been studied. It is found that the particle size of RDX is increased with water content or the concentration of RDX solution and the particle size of RDX prepared using DMSO as solvent is under20nm, which is smaller than that prepared using DMF as solvent. Moreover, the infrared spectrogram of raw RDX and sub-micron RDX almost have no difference. TG figure shows the mass of raw RDX and sub-micron RDX are both slowly decreased at about200℃, and sharply declined in the rang of200℃～250℃, while the decline percentage in mass of sub-micron RDX is lower than that of raw RDX. In addition, by analyzing DSC curve, it is found that endothermic temperature and exothermic temperature of the raw RDX and sub-micron RDX are respectively about205℃and236℃, while heat release of sub-micron RDX is larger than that of raw RDX; With increase of heating rate, thermal decomposition peak temperature and heat release of raw RDX and sub-micron RDX are both gradually increased. The apparent activation energy, impact sensitivity and friction sensitivity of sub-micron RDX are all lower than that of raw RDX.