Study On Process Of HMX By Acetic Anhydride Method

HMX,currently used a military explosive,and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetraz- ocine is known to be an explosive of great power,high detonation performance and good thermal stability.Through analyzing and simulation,the paper points out the geometrical forms of hexamethylenetetramine in nitric acid; the process of synthesis HMX influencing on the yield and purity of HMX was introduced;the factors influencing on the synthetic process of HMX were investigated by DPT;the ingredients of wastewater and crude sample of HMX were analyzed.The paper presents the geometrical forms of hexamethylenetetramine in nitric acid based on the Interaction among Molecules and Chemical Bond Properties. Molecular modeling is a better method for optimization of hexamethylenetetramine mononitrate and hexamethylenete- tramine dinitrate.The main results of the study are as follows: HA is mainly in the form of hexamethylenetetramine mononitrate and the structure (a) of hexamethylenetetramine mononitrate is the main form.The effect of the concentration of nitric acid and acetic anhydride on the general rate of HMX was studied as well as the effect of the reaction temperature and time on the yield and purity of HMX was investigated in the process of synthesis HMX. The results show that, the best result could be obtained when the feeding and holding time were 30~40min, the purity of crude HMX and the yield of pure HMX were 80.1% and 53.5%, respectively.The DPT was synthesized based on the lines of modified Bachmann route.Firstly, the intermediate DPT has been preparated by using hexamine as starting material. And then, the HMX has been synthesized by nitrifying DPT. The effect of the reaction temperature and the concentration of NH4NO3 on the yield of HMX was researched. The results show that the yield can reach 67.2% under the optimum conditions,which means reaction temperature is 25℃, NH4NO3 and DPT are added with 2g and 1g in 10ml HNO3, respectively.The crude HMX was determined by thin layer chromatographic separation. The sample was separated by developing solvent of nitromethane /dichloromethane (1/2). The pure compounds have been characterized on the basis of infrared spectroscopy. It was found that 4 compounds were isolated and identified. They are RDX,HMX,TAX and SEX.The organic pollutants were absorbed by LS-100 resin from wastewater and eluted with dichloromethane/acetonitrile (80/20). The sample was separated by developing solvent of dichloromethane/acetonitrile/methanol/acetic acid(20/3/1/0.1). In this paper TLC is presented to separate organic pollutants in wastewater and to analyze them by IR and HPLC.A SINOCHROM ODS-BP(150mm×4.6mm,5μm)column was used,and the mobile phase consisted of water, methanol and acetonitrile(70/10/20). The detection wavelength was 235nm. The results show that 7 compounds were isolated and identified by TCL.Reversed phase HPLC was applied for the retention times determination of the compounds in wastewater.Under the selected conditions,the retention times of DPT,SEX,TAX,HMX,RDX, BSX and AcAn were 2.91,3.34,5.03,16.17,17.91,33.98 and 50.97min respectively.