Design,Preparation And Characterization Of ANZPO Based Cocrystal

Cocrystal is a new method to improve the performance of energetic materials and balance the high energy and low sensitivity from the molecular level.A cocrystal explosive consisting of 2,6-Diamino-3,5-dinitropyrazine-1-oxide(ANPZO)and cyclotetramethylenetetramine(HMX)was prepared as an ANPZO based cocrystal explosives in this paper.The methods of design,preparation and characterization were also studied in this paper.The main contents are as follows:(1)According to the principle of hydrogen bond formation and the bonding rules of functional groups,HMX was chose as precursor and the ANPZO/HMX cocrystal explosive was designed by analogy.(2)Molecular dynamics method was used to calculate the interaction between different molecules.The results show that the intermolecular force between ANPZO and HMX is greater than that of ANPZO itself and HMX itself.Cohesive energy density indicates that ANPZO based cocrystal technology can reduce the sensitivity of HMX.The radial distribution function shows that there are hydrogen bond and van edward force in ANPZO/HMX cocrystal system.(3)Attachment energy model was used to predict the growth surface of ANPZO in vacuum and calculate the effects of the crystal plane and solvent on ANPZO based cocrystal.The results show that cocrystal of ANPZO and HMX occurs mainly on(0 1 1)and(1 0 1)surfaces of ANPZO.In DMSO and DMF solvent,the cocrystal occurs mainly on(0 1 1)surface of ANPZO.ANPZO and HMX are more likely to from cocrystal in DMSO solvent.(4)The preparation technology of HMX/ANPZO cocrystal was studied.Cocrystal explosives were prepared by ultrasound-assisted gas diffusion method,using DMSO as solvent and water as anti-solvent.The molar ratio of ANZPO and HMX is 1:2.(5)DSC,SEM,IR and XRD were used to characterize the explosives.DSC tests showthat ANPZO/HMX sample has a unique thermal decomposition characteristics.As can be seen from the IR,SEM and XRD results,the structure of ANPZO/HMX is different from HMX and ANPZO.(6)Mechanical sensitivity testing of ANPZO/HMX sample show that the characteristic drop height is 59 cm,which is 96.7% higher than HMX.The results indicate that the sample with ANPZO can reduce the sensitivity of HMX.The theoretical detonation velocity reaches9090 m/s,which shows little difference with the detonation velocity of HMX.The above results indicate that cocrystal technology can reduce the sensitivity of HMX while maintaining the high energy output characteristics of HMX.