مجله تحقیق و توسعه مواد پرانرژی
سال ششم شماره 1 (پیاپی 11، بهار و تابستان 1389)

There are different methods for enhancing burning rate of double base propellants. One of this methods is changing composition of the propellant, but if we want enhance burning rate without changing the propellant composition, we must use special methods such as using embedded metal wires. By this method we can increase the burning rate for 400 to 500 percent. This enhancement in burning rate is influenced by wire type and wire diameter. This article discusses about methods of embedded wire in double base propellants and parameters such as material, diameter, thermal conductivity, thermal diffusivity of wire and the gap of wire and propellant.

A major challenge in the production of UDMH is the high energy cost associated with the separation of UDMH from the large excess of water. The Pressure Swing Adsorption (PSA) process is attractive for the final separation since it requires little energy input and is capable of producing a very pure product. At this research, a pilot-scale PSA process was designed and manufactured. The possibility separation of UDMH-water mixtures by adsorption on 3A nanopore zeolites has been investigated. The column was operated under the following operating variables: feed concentration (85-90-95%), adsorption temperature (85-125◦C) and adsorption pressures (0, 0.5 and 1.5 bar). The water concentration, temperature and pressure of process parameters have been varied in order to establish their influence on the PSA performance. The effect of these variables on the enrichment percentage of the product was studied.

In this article the W/ZrC composite, as a material suitable for high temperature applications, has been investigated. Considering the difficulties and high costs of the graphitic components, in recent years there was a growing interest to provide low-cost W/ZrC composites as an alternative to carbon- carbon composite. This composite is a promising material for rocket and jet engine components like nozzles, valves, combustion liners, exhaust flaps and leading edges, so its production is the aim of defense industry in most advanced countries, such as the United States, Russia and China. A desirable property for this composite is its inexpensive and simple fabrication method that is feasible with available equipment and facilities within the country. The carbide phase in the composite leads to creep resistance at high temperatures and because of tungsten the flexibility and fracture resistance of composite is high. In this study while the properties of W/ZrC composite are investigated, its application especially in the arms industry is mentioned and finally the methods of fabrication including Hot-press, Displacive Compensation of Porosity and reaction sintering has been studied.

Emulsion explosives are commercial explosive material includes an organic phase as fuel and an aqueous phase consist of mineral salt as oxidizer, which produce in form of viscose and gel- like. In other hand, waste powders are such propellants that will be expired and be unusable thus should be destructed in any way. In this study for economical destruction of waste propellants, they add to bulk emulsion explosive in grinder form an as filler. The obtain results are shown apparently that addition of this powder to bulk emulsion caused to increase in explosion rate without change in their physical and chemical properties. Also, using of this powders in bulk emulsion explosive formulation gain economic cost.

The inhibition of double-base (DB) solid propellants is performed in order to control burning surface and increase burning time. The choice of materials for use as an inhibitor depends upon the type of propellant. For DB propellants, cellulosic derivatives such as cellulose acetate, ethyl cellulose and different filled/ unfilled flexible polyesters are used. An inhibitor must have the most resistance against diffusion of nitroglycerin from the DB propellant to the inhibitor. It must be compatible with the propellant in the chemical sense. Some flame retardant materials such as antimony trioxide and halogenated materials and alumina trihydrate are employed in combination of inhibitors for burning process control.

Otto fuel II is a type of monopropellant that was formed from propylene glycol dinitrate, di butyle sebacate and 2-nitro diphenyleamine. Therefore above propellant was tested by using of submitted experiments in standard military product. The experiments which is done in this part, consist of PGDN specified percent in blank by useing of potentiometric method and measuring amount of 2-NDPA by useing of ultraviolet sepectroscopy and calculation of DBS amount. Meanwhile the IR spectroscopy blank and synthesis sample was prepared and compared which were completely in accordance with each others.The use of this propellant is in intelligent undersurface torpedo MK 48,MK 46 as fuel. The important factor of this propellant is unsubstituted enistent of propylen glycule dinitrate with other usual nitrate esters. This invention describe nitration of propylene glycole and above propellant was formulated and produced according to the result of blank analysis after chemical and physical analysis of blank propellant otto fuel II.

Access to various rifle projectiles is carried out by using of different compounds in various propellants. Therefore analysis and quantifying of coexisting ingredients in unknown samples are greatly helpful to produce of the same propellants by reveres engineering. The basic problem on this analysis is structural similarities of primary compounds in formed sample after producing. Correct determination and quantities are only carried by using of sensitive instruments or innovative laboratory methods. In this research, a new technique was developed for separation and determination of some ingredients in unknown double-base propellant. In this work after separation and measurements of nitroglycerin (NG), 2-nitro diphenylamine (2-NDPA) and dienpropyladipate (DPA) by reflux technique and HPLC system. Then the other ingredients including nitrocellulose (NC), lead resorcylate, copper resorcylate and lead salicylate were separated by an easy and classic method based on the selective solubility of these compounds in some solvent mixtures. After the separation, the ingredients were determined with infrared (FT-IR) spectrometry, melting point and weighing techniques. Finally emission atomic spectrometry (ICP-AES) method was used to determination of Pb and Cu cations in the initial sample and the separated ingredients. The analytical results were suitable and comparable to each other.