JOURNAL OF ENERGETIC MATERIALS
Year:2016 | Volume:10 | Issue:4 (28)|Papers Count:9

In the synthesis of hexamethylenetetranitramine (HMX) by Bachmann method, the morphology of crude HMX products are needle-like with alpha polymorph. This quality of materials leads to separation of a-HMX from final suspension to be time-consuming and difficult. On the other hands, crude product of a-HMX are the more sensitive and unsafe than b-HMX. Herein, a seeding strategy was developed in the synthesis of HMX by hexamine and 1, 5-dinitroendomethylene-1, 3, 5, 7-tetraazacyclooctane (DPT) as raw materials, to control the polymorphism of the crude products from a to b type, and their morphology from needle-like to spherical shape. Therefore, the microparticles of b-HMX, as micro-seeds, were added to the nitrator in the various steps of production process from hexamine and DPT reactants, then the yield of process was determined and morphology of products were characterized using X-ray diffraction spectroscopy (X-ray) and optical microscopy. The results show that this interesting technique can control the polymorphism and structure of crude HMX from a to b type, improving the safety of crude product and its filtration time. Also, micro-seeding provides a useful conditions to the preparation and crystallization of b-HMX.

Epoxy resins are the most important polymeric materials used in the preparation of thermal insulator in double base rocket propellants. In this work, Taguchi statistical method was used for the flexural strength investigation of epoxy resins (after curing). The effects of the type of resin, concentration of diluent (phr), type of curing agent and concentration of curing agent were investigated on the flexural strength and data given of ANOVA showed that the type of curing agent with 46.9 percent has the highest influence on the flexural strength of the epoxy insulator. The data given of ANOVA showed that the best flexural strength of 96.6±13.3 MPa was obtained for the optimum conditions of MANA POX-102 as epoxy resin, H-35 as curing agent with 57 phr. In comparison, practical result of flexural strength with three replicate runs was obtained 92.3±3.8 MPa. Finally, adhesion strength for optimal sample on the surface of a double base propellant by Pull-off test with three replicate runs was resulted as 2.2±0.1 (n=3) MPa.

Titnium diboride is a wear-resistant compound having high hardness, low density and high electrical and thermal conductivity in the solid state. In this study, the explosive powder metallurgy process for production of samples from TiB2 powder was investigated. At first, analytical solution of the explosive powder metallurgy process with water as interface medium was performed in order to determine the suitable explosive material to consolidate the TiB2 powder. In the experimental section, with the different design of assemblies the pieces were produced with this method. Analysis of the density and hardness of the produced parts showed that the use of momentum traps with proper height and titanium powder in the assemblies, can reduce the shock wave stretching back into the die and produce disks with relative density of 98% and a hardness of 2600 Vickers. In addition, investigation of the microstructure of the produced components using scanning electron microscopy showed that there was a good connection between the powder particles and the samples were free of any cracks.

Glycidyl nitrate is a valuable energetic material of oxiranes family that is used as an energetic monomer in the manufacture of poly (glycidyl nitrate) as an energetic binder. In this study, the effect of different catalysts on one pot synthesis of glycidyl nitrate by epichlorohydrin was investigated. The main purpose of this research is to find an effective catalyst for improving the yield of the reaction under mild conditions. For this purpose, several catalysts were used for the nitration reaction by nitric acid. The results showed that the synthesis of glycidyl nitrate in the presence of nano Fe3O4 gave the highest yield (72%) compared to the other catalysts. Finally, the product was characterized by FTIR spectroscopy and 1HNMR.

The rapid and simple detection of trace explosives, such as 2, 4, 6-tri nitrotoluene (TNT), is very important in countering terrorist threats and pollution of soil and goundwater. Nowadays, quantum dot (QD)-based fluorescent sensors for TNT detection have attracted significant attention because of the unique features of QDs. In this paper, for the first time, a novel method using thioglycolic acid-capped CdTe QDs has been presented to assay TNT. CdTe QDs were synthesized with high quality (2.8 nm) in aqueous phase and were used as fluorescent probe for detection of TNT. The response was linearly proportional to the concentration of TNT in range of 0.6 to 300 mM with a detection limit of 0.037 mM. The calculated Stern–Volmer quenching constant was 1293 M1. The relative standard deviation for five replicate determinations was estimated at 3.3% for TNT with concentration of 140 mM. Studies on the selectivity of this proposed method demonstrate that only TNT can create an intense signal response (The uorescence quenching percentages obtained for each analyte were 16%, 7% and 4% for TNT, 2, 4DNT and 2NT, respectively). Therefore, the thioglycolic acid capped CdTe QDs are excellent nanomaterial for TNT detection.

Multiple formed projectile is more effective than the single types. Calculation and estimation of multiple projectiles formation behavior is one of the problems that engineers face with it. Given the complexity of issues analysis of explosive detonation, shock wave propagation, liner deformation during the formation of projectiles and its penetration in target, numerical simulation of formation and penetration of the projectiles can play a decisive role in the anti-armor warheads design. In this study, the formation and penetration of central and lateral projectiles have been simultaneously investigated by lsdyna finite element code. Comparison of numerical simulation shows good agreement with experimental test. In addition, the empirical test show that the central projectile and the lateral projectiles have penetrated about 5 cm and about 1 cm, respectively. The hitting deviation of lateral projectiles from the center is about 130 cm, with a maximum of 5% difference between the experimental and numerical results.

N,N’-bis (2-hydroxypropyl)aniline (Isonol C100) is an alkanolamine. This compound is intended to increase the chain length of curing composite solid propellants, stabilize and soften the double base propellants, and assist in the softening of the ethyl cellules. Isonol C100 was synthesized through the reaction of propylene oxide and aniline at a pressure of 7 bar, a temperature of 125oC and in the presence of lithium Bromide as catalyst. Due to the existence of active sites on propylene oxide, different catalytic and temperature conditions can causes the production of propylene glycol and polypropylene glycol, in addition to the production of undesired and additional products which reduces the purity of the final product and decrease the reaction efficiency. Control of the parameters such as the temperature, method of addition of materials, injection of nitrogen gas, and pressure, can increase the reaction efficiency and product purity. The advantages of this method include the low temperature reaction and absence of solvent. Propoxylation products were determined by GC/MS, separated by column chromatogaphy, and characterized using the 1H-NMR, 13C-NMR, and IR spectrometry.