Methyl Nitroguanidine Low And Its Performance Study Between Eutectic Composition Components

Characterized by low cost, good safety and high energy, the eutectics based on methyl-nitroguanidine (MeNQ) have been proposed as potential substitute for TNT recently. The first formulation of MeNQ-based eutectic system with mass ratio of MeNQ/NQ/AN/AP=43.5/10.5/10/36was proposed by Michael in1990and had been utilized as a component in AFX-453cruise missile. However, the melting temperature of this formulation (100℃) is too high to be applicable to vapour melt-cast technology. In addition, both the mechanical performance and safety need to be enhanced. Though extensive studies have been focused on the formulation and properities of eutectic systems based on MeNQ, few data about their microstructure and morphology have been presented.In this paper, hydrazine nitrate (HN) was added to reference formulation as a melting point depressant. Binary, ternary, and mutil-composition eutectic system based on MeNQ was obtained by thaw-melt method. The microstructure and performance of such systems were characterized by molecular simulation, surface and interface morphology technology, which will provide some guide for development of formulation for TNT replacement. It is anticipated that these research could help us to understand and develop new eutectic mixture based explosive formulations as TNT replacement, accelerate the application of melt-cast explosives which is not based on TNT.The influence of material proportion on melting temperature, mechanical properties, ignition and booster feature et al. are investigated. The DSC is used to identify the melting and crystallization behavior of the eutectic in order to obtain the melting dynamic of the eutectic, primary master the transformation rule and try to explain the formation mechanism. The main results are as follows:(1) Binary eutectic mixtures with low melt temperature of HN and MeNQ can be formed between wide molar ratio range which is benefit for the research of ternary, and mutil-composition energetic eutectic system.(2) The fusion enthalpy value of MeNQ-HN、NQ-HN binary eutectic calculated from excess thermodynamic functions have indicated that the eutectic is not simply a mechanical mixture of the two components but there is some type of interaction between them. The result was confirmed by IR spectral studies and x-ray diffraction experiment. Density functional theory calculations have shown the possibility of the formation of an weak H-bond between the H-atom of the NH2group and the O-atom of the NO2in the eutectic mixture. The most stable configuration of MeNQ-HN binary eutectic could be present at mol ratio of3:2. Differently, the most stable configuration of NQ-HN binary eutectic is three HN-two NQ, which agree with the experimental results.(3) Staged crystallization phenomenon appeared during the recrystallization procedure after melting. AP crystal first with crisscross pattern as crystal nucleus. With the temperature declined slowly, MeNQ crystal quickly around the AP and occupied the crystal process. When the temperature arrived at70centigrade, HN with lowest melt temperature start to crystal. The phenomenon above cause the non-homogeneous of the sample.(4) The melt temperature of all new formulation is low than100centigrade, and all of these formulations could detonation, but energy of detonation is lower than TNT. It is predicted that the copper tube radius expansibility of these formulation is bad and it is not suitable for cylinder test to evaluate the power. The ignition and booster feature of the eutectic formulation can not be accelerated by hydrazine nitrate and ammonium perchlorate which have high energy. It is necessary to adjust the new formulation if we want to obtain high energy eutectic mixture.(5) The eutectic formulation is easy to absorb moisture after addition HN. Moreover, both of the thermo properties and mechanical properties cannot satisfy the requirment of melt-cast explosive liquid carrier. It seems reasonable to conclude that HN is not suitable for the liquid carrier of melt-cast explosive.