Polymeric fuel component

The oxygen molecules produced by the decomposition act as an oxidizer when AP particles are mixed with a polymeric fuel component, for example ... 

The perchlorates used for propellants and explosives are ammonium perchlorate (AP NH4CIO4), nitronium perchlorate (NP N02C104), and potassium perchlorate (KP KCIO4). AP is the major crystalline oxidizer used for composite rocket propellants. The oxygen molecules produced by the decomposition act as an oxidizer when AP particles are mixed with a polymeric fuel component, for example,... 

Typical crystalline materials used as oxidizers are perchlorates, nitrates, nitro compounds, nitramines, and metal azides. The polymeric materials used as fuel components are divided into nitrate esters, inert polymers, and azide polymers. Optimized combinations of these oxidizer and fuel components yield the desired ballistic characteristics of propellants or explosives. 

Polymeric materials that act as fuels and oxidizers are composed of nitrogen, oxygen, carbon, and hydrogen atoms. The hydrocarbon structures act as fuel components, and the oxidizer fragments, such as -C-NOj, -O-NOj, -O-NO, or -N-NO2, are attached to the hydrocarbon structures through covalent chemical bonds. 

The burning rate of propellants is one of the important parameters for rocket mo-tordesign. As described in Section 7.1.2, the burning rate of AP composite propellants is altered by changing the particle size of the AP used. The diffusional mixing process between the gaseous decomposition products of the AP particles and of the polymeric binder used as a fuel component determines the heat flux feedback from the gas phase to the condensed phase at the burning surface. - This process is a... 

Since rocket propellants are composed of oxidizers and fuels, the specific impulseis essenhally determined by the stoichiometry of these chemical ingredients. Ni-tramines such as RDX and HMX are high-energy materials and no oxidizers or fuels are required to gain further increased specific impulse. AP composite propellants composed of AP particles and a polymeric binder are formulated so as to make the mixture ratio as close as possible to their stoichiometric ratio. As shown in Fig. 4.14, the maximum is obtained at about p(0.89), with the remaining fraction being HTPB used as a fuel component. 

The selechon of fuel components to be mixed with oxidizer components is also an important issue in the development of pyrolants for various applications. Metal particles are used as fuel components to develop small-scale pyrolant charges as deployed in igniters, flares, and fireworks. Non-metal particles such as boron and carbon are used to formulate energetic pyrolants. Polymeric materials are commonly used as fuel components to develop relatively large-scale pyrolant charges, such as gas generators and fuel-rich propellants. 

Aluminum (Al) is a silver-colored light and soft metal used as a major component of aluminum alloys, which are used to construct aircraft and vehicles, similar to Mg alloys. However, Al is known as a readily combustible metal. Thus, Al particles are used as major fuel components of pyrolants. Al particles are mixed with ammonium perchlorate particles and polymeric materials to form solid propellants and underwater explosives. The reaction between aluminum powder and iron oxide is known as a high-temperature gasless reaction and is represented by ... 

Polymeric materials used as fuel components of pyrolants are classified into two types active polymers and inert polymers. Typical active polymers are nitropoly-mers, composed of nitrate esters containing hydrocarbon and oxidizer structures, and azide polymers, containing azide chemical bonds. Hydrocarbon polymers such as polybutadiene and polyurethane are inert polymers. When both active and inert polymers are mixed with crystalline oxidizers, polymeric pyrolants are formed. 

When AN powder is mixed with a polymeric material, the oxygen gas produced by the decomposition of the AN powder reacts with the hydrocarbon fragments of the thermally decomposed polymeric material. The major combustion products are GO2 and H2O. Nitropolymers are not used as fuel components of AN pyrolants because of the reaction between the NO2 formed by their decomposition and the AN powder. This reaction occurs very slowly and damages the physical structure of the AN pyrolant. Instead, polymeric materials containing relatively high mass fractions... 

As described in Sections 4.2.4.1 and 5.2.2, GAP is a unique energetic material that burns very rapidly without any oxidation reaction. When the azide bond is cleaved to produce nitrogen gas, a significant amount of heat is released by the thermal decomposition. Glycidyl azide prepolymer is polymerized with HMDI to form GAP copolymer, which is crosslinked with TMP. The physicochemical properties of the GAP pyrolants used in VFDR are shown in Table 15.3.PI The major fuel components are H2, GO, and G(g), which are combustible fragments when mixed with air in the ramburner. The remaining products consist mainly of Nj with minor amounts of GOj and HjO. 

Fuel performance problems initiated by light are not common. However, fuel quality can be affected. The primary concern of light exposure is fuel color darkening and the possible formation of high-molecular-weight deposits due to free-radical-initiated polymerization of fuel components. 

Double bonds between carbon atoms in fuel components are active sites for oxidative attack and polymerization. During long-term storage and during the combustion process, oxidation and polymerization of olefinic compounds can result in the following ... 

During the processing of fuels, acids such as sulfuric acid and hydrofluoric acid are used. Sulfuric acid can be used to polymerize fuel olefins and remove components from fuel such as mercaptans and thiophenes. Sulfuric and hydrofluoric acids are used in the alkylation process to produce high-octane, branched paraffins. Carryover of these acids into fuel can initiate ferrous metal corrosion. 

Use Polymerization of isoprene and butadiene intermediate in preparation of lithium hydride rocket fuel component metalating agent. 

Use Intermediate for accelerators, dyes, pharmaceuticals, insecticides, fungicides, surface active agents, tanning, dyeing of acetate textiles, fuel additive, polymerization inhibitor, component of paint removers, solvent, photographic developer, rocket propellent. 

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