Papers by Keyword: Ammonium Perchlorate

Abstract: A new generation of high energy materials depends on the use of Nano-particle oxides. Nano-scale copper oxide (nano-CuO) has large surface area and surface energy which is suitable for its application in the field of energetic materials. This manuscript reports a method for the synthesis of nano-CuO by a liquid-state reaction method. The prepared nano-CuO was characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD) to check the particles size, purity and morphology of the crystals. The effect of Nano-CuO on the thermal behavior of AP was tested by differential scanning calorimeter (DSC). The results proved that the average particle sizes of the nano-cuo particles are in the range of 10-20 nm. The thermal degradation rate of AP was increased by 23% in the presence of 1% nano-CuO and the heat release was increased by 51%. It was concluded that nano-CuO could have obvious effect on the burning behavior, performance and combustion characteristics of the solid rocket propellants.

Abstract: The Closed vessel (CV) is an equipment used to study the ballistic parameters by recording burning time history, pressure buildup during the process and vivacity of the propellants. It is an apparatus which consists of strong pressure vessel, piezo-electric pressure transducers, sensors and dedicated software. To save time and resources this method is employed instead of dynamic firing while doing research and development of propellants. A measured amount of propellant charge is loaded in the vessel and fired remotely. Ignition is provided by the filament which ignites the black powder charge. In this study, we have used Closed Vessel Tests (CVT) for the first time for recording the ballistic parameters of slow burning composite rocket propellant. We developed a set of composite solid propellant samples containing a mixture of bimodal Ammonium Perchlorate (AP) as an oxidizer, Hydroxy-terminated Polybutadiene (HTPB) as a binder as well as fuel, Dioctyl Sebacate (DOS) as plasticizer, 1-(2-methyl) Aziridinyl Phosphine Oxide (MAPO) as bonding agent and Toluene Diisocyanate (TDI) as curator. Samples were developed by changing the solid loading percentage of bimodal AP particles. By increasing the percentage of AP, the oxidizer-fuel ratio (O/F) increases which effects the ballistic parameters. It is observed that maximum pressure and vivacity increases with increase in solid filler in the propellants. As quantity of AP increases, rate of rise of pressure also increases. CVT firing of each sample was done three times to obtain average burning time and pressure buildup history to evaluate the effect of oxidizer loadings on ballistic parameters of the composite propellant.

Abstract: One of the key factors that play an important role in the performance of a solid propellant rocket is dependent on its burning rate. A strand burner is a type of apparatus used to measure the propellant burning rate at elevated pressure. This study investigates the relation between burning rates of aluminized ammonium perchlorate at low pressure. Chamber pressure was varied from 1 atm, 3 atm, 5 atm and 7 atm. This study shows that propellant burning rate is about 50%-62% higher when the burn rate test is conducted at atmospheric condition compared to when it is done in inert gas. The investigation’s results also revealed an increasing propellant burning rate when the chamber pressure is increased. In conclusion, the burning condition and chamber pressure influences the propellant burning rate.

Abstract: Recent applications of transition metal nanoferrites as catalyst in thermal decomposition of ammonium perchlorate (AP) and combustion of composite solid propellant (CSP), have been reviewed. Catalytic applications include the use of mainly cobalt, nickel, copper, zinc, manganese, cadmium nanoferrites, as well as their mixed-metal combinations. The nanoferrites are obtained mainly by wet-chemical, sol-gel, solvo-thermal, auto-combustion and co-precipitation methods. Addition of nanoferrites to AP led to shifting of the high temperature decomposition peak toward lower temperatures which shows their catalytic activity. The burning rates of CSPs have also been enhanced by these nanoferrites. Contents of Paper

Abstract: Ammonium perchlorate (AP) based solid propellant is a modern solid rocket propellant used in various applications. The combustion characteristics of AP based composite propellants were extensively studied by many research scholars to gain higher thrust. The amount of thrust and the thrust profile, which may be obtained from a specific grain design, is mainly determined by the propellant composition and the manufacturing process that produces the solid propellant. This article is intended to review and discuss several aspects of the composition and preparation of the solid rocket propellant. The analysis covers the main ingredients of AP based propellants such as the binder, oxidizer, metal fuel, and plasticizers. The main conclusions are derived from each of its components with specific methods of good manufacturing practices. In conclusion, the AP based solid propellant, like other composite propellants is highly influenced by its composition. However, the quality of the finished grain is mainly due to the manufacturing process.

Abstract: Ni/Co/Cu/Fe nano-composite oxides (Ni/Co/Cu/Fe–NCOs) were prepared by calcination of Ni/Co/Cu/Fe hydrotalcites (Ni/Co/Cu/Fe–HTs) precursors. Ni/Co/Cu/Fe–NCOs were used as new catalysts on improving thermal decomposition of ammonium perchlorate (AP). Their catalytic activities were investigated using DTA and TG–MS. The results revealed that Ni/Co/Cu/Fe–NCOs exhibited NiO and spinel phase with high specific surface areas of 90–120 m² g^–1. They have homogenous particles with average crystallite size in the range of 50–60 nm. The thermal decomposition process of AP can be accelerated by the addition of Ni/Co/Cu/Fe–NCOs. Ni/Co/Cu/Fe–NCOs achieved the purpose of improving thermal decomposition of AP based on the presence of superoxide ion (O₂^–) on the surface of Ni/Co/Cu/Fe–NCOs.

Abstract: Mg2NiH4 was prepared by replacement-diffusion method, and its structure was determined by XRD、ICP and DSC-TG. The influence of Mg2NiH4 on the thermal decomposition behaviour for ammonium perchlorate (AP) was carried out by thermal analysis (DSC). Results show that Mg2NiH4 has obvious catalytic effect on the thermal decomposition of AP. This catalytic effect of Mg2NiH4 was enhanced with its increase in content, and the DSC heat release for AP was on its biggest value when the content of Mg2NiH4 was 30%. With the increase of hydrogen storage, the catalytic effect of Mg-Ni hydrogen storage alloys became stronger.

Abstract: A series of Cu/Cr nanocomposite oxides (Cu/Cr–NCOs) were prepared by Cu/Cr hydrotalcite precursors. Their catalytic activities on thermal decomposition of ammonium perchlorate (AP) were investigated by differential thermal analysis (DTA). The results show that Cu/Cr–NCOs are efficient in enhancing thermal decomposition of AP. With 4 wt. % addition of 500 °C calcined Cu2Cr–NCOs, the thermal decomposition process of AP can be accelerated by 107 °C. Cu/Cr–NCOs catalysts have better effect compared to mechanical mixture of CuO and Cr2O3 catalyst. Their catalytic mechanism was also discussed.

Abstract: Effects of various grain sizes (10~390 µm) under heating rate of 40 °C/min on ammonium perchlorate (AP) decomposition characteristic parameters, the decomposition thermal behavior and kinetic parameters (activation energy and pre-exponential factor), were investigated by simultaneous DSC/TGA in a dynamic nitrogen atmosphere. In addition, the specific surface areas were measured by the BET-method. Moreover, the kinetic parameters were determined by a simplified approach based on the isoconversional method. The results showed that, the higher the AP particle size the lower the determined decomposition kinetic parameters. In addition, the results were in acceptable agreements with some important literatures. Moreover, it was highly recommended to apply the higher agreeable heating rates for AP samples to determine that parameters more accurately.

Abstract: In this paper, experimental investigation of pressure exponent in burning rate of composite propellant was conducted. Four sets of different propellant compositions had been prepared with the combination of Ammonium Perchlorate (AP) as an oxidizer, Aluminum (Al) as fuel and Hydroxy-Terminated Polybutadiene (HTPB) as fuel and binder. For each mixture, HTPB binder was fixed at 15% and cured with isophorone diisocyanate (IPDI). By varying AP and Al, the effect of oxidizer-fuel mixture ratio (O/F) on the whole propellant can be determined. The propellant strands were manufactured using compression molded method and burnt in a strand burner using wire technique over a range of pressure from 1atm to 31atm. The results obtained shows that the pressure exponent n, increases with increasing O/F. The highest pressure exponent achieved was 0.561 for propellant p80 which has O/F ratio of 80/20.