Study On The Quality Control Of HMX Preparation Process

Cyclotetramethylenete-tranitramine(HMX)with high-density,high-energy and excellent thermal stability,is one of the single compound explosives with excellent comprehensive properties.In the process of HMX preparation,the stability fluctuation of the raw material component affects the stability of the preparation process.Besides,crystal morphology and crystal size have a significant influence on HMX performance.Therefore,in this thesis,molecular dynamics(MD)simulation method and instrumental analysis technology were used to achieve the rapid detection of raw material components in HMX preparation process,and the control of HMX crystal morphology and particle size.And the research results would be of great significance to the control of HMX preparation process.The main study contents are as follows:(1)The rapid analysis models of raw materials composition content of HMX preparation process were established.For the hexamethylenetetramine-acetic acid and acetic acid raw materials systems in HMX preparation process,the quantitative analysis models of the hexamethylenetetramine-acetic acid solution,acetic acid-water solution,and hexamethylenetetramine-acetic acid-water solution three systems have been established respectively by near infrared spectroscopy method(NIR),taking into account temperature factor,combined with partial least square(PLS)method and principal component regression(PCR)method to statistical analysis.The accuracy and precision of the three models were evaluated.The results showed that the relative error of hexamethylenetetramine-acetic acid system model for quantitative analysis of hexamethylenetetramine content was 0.21%,the repeatability of the method was 0.16%.The analysis period is about 5 minutes,which can save time cost compared to titration analysis method(2 h).The models can be applied to the raw material analysis during HMX preparation process.(2)The effect of additive content(acetone is as solvent,ethyl acetate is as additive)onβ-HMX crystal morphology was investigated by MD simulations method.The results revealed that adding appropriate additives can effectively control the crystal morphology ofβ-HMX and reduce the aspect ratio of crystal,which makes the crystal closer to the sphere.(3)The solubility properties of β-HMX in solvent were determined by the equilibrium method,the relative standard deviation of the correlation solubility equation is less than0.05,which providing the corresponding solubility parameters to study the control ofβ-HMX particle size.And the effects of stirring speed,cooling rate and mother liquor concentration on β-HMX crystal size during the crystallization process were studied through the focused beam reflectance measurement.The reliable experimental basis and theoretical basis were provided to obtain the required size of β-HMX product.