Polymeric Fuels

Composite proplnts, which are used almost entirely in rocket propulsion, normally contain a solid phase oxidizer combined with a polymeric fuel binder with a -CH2—CH2— structure. Practically speaking AP is the only oxidizer which has achieved high volume production, although ammonium nitrate (AN) has limited special uses such as in gas generators. Other oxidizers which have been studied more or less as curiosities include hydrazinium nitrate, nitronium perchlorate, lithium perchlorate, lithium nitrate, potassium perchlorate and others. Among binders, the most used are polyurethanes, polybutadiene/acrylonitrile/acrylic acid terpolymers and hydroxy-terminated polybutadienes... 

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

The polymeric hydrocarbon also acts as a binder of the particles, holding them together so as to formulate a propellant grain. Ammonium perchlorate (AP) is a typical crystalline oxidizer and hydroxy-terminated polybutadiene (HTPB) is a typical polymeric fuel. When AP and HTPB are decomposed thermally on the propellant surface, oxidizer and fuel gases are produced, which diffuse into each other and react to produce high-temperature combustion gases. 

Advanced PEM Fuel Cells. APOLLON. Coals Development and construction of Advance polymeric fuel cells which will be able to operate under Hj and/or methanol fuels, aiming to thermodynamic efficiencies exceeding 50% with power densities of the order of 1 W/cm and significantly reduced manufacturing cost of the membrane electrodes assembly. 

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. 

Oxidized and polymerized fuel degradation products can increase existent gum... 

Composite rocket propellants are two-phase mixtures comprising a crystalline oxidizer in a polymeric fuel/binder matrix. The oxidizer is a finely-dispersed powder of ammonium perchlorate which is suspended in a fuel. The fuel is a plasticized polymeric material which may have rubbery properties (i.e. hydroxy-terminated polybutadiene crosslinked with a diisocyanate) or plastic properties (i.e. polycaprolactone). Composite rocket propellants can be either extruded or cast depending on the type of fuel employed. For composite propellants which are plastic in nature, the technique of extrusion is employed, whereas for composite propellants which are rubbery, cast or extruded techniques are used. 

Burning-Rate Tests of Pyrotechnic Mixtures Containing in Situ Polymerized Fuel yrup a... 

New catalysts of hydrogen oxidation for low-temperature fuel cells are molybdenum and tungsten carbides [2, 3], For solid polymeric fuel cells the novel catalysts by plasma treatment of polymer membrane have been developed. The radicals at surface are generated. These radicals are catalysts of anodic reactions [4]... 

For polymeric fuels, the analysis of Section 7A is relevant to the evaluation of therein denoted by... 

Composite rocket propeiiants. This type of propellant contains two-phase mixtures with a aystalhne oxidizer in a polymeric fuel or binder matrix. The finely dispersed powder of ammonium perchlorate suspended in a fuel is the oxidizer. The fuel is a plasticized polymeric material such as hydroxy-terminated polybutadiene cross-linked with a diisocyanate (rubber ts e) or carboxy-terminated polybutadiene (plastic type) [4]. 

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,... 

Medium-temperature (Fe-Cr) and low-temperature (Cu) catalysts were used for a decrease in CO content by shift reaction (see Fig. 3). The use of these catalysts allowed reducing CO concentration in synthesis gas for the test of polymeric fuel cell stack. Electric capacity of this stack can be up to 400 W. In this case, complete conversion of natural gas and CO is reached. 

Proton exchange membrane fuel cell or Polymer eleetrolyte membrane fuel cell or Polymer electrolyte fuel eell or Polymeric fuel eell or Polymerie membrane fuel cell or Direct methanol fuel cell or DMFC... 

Bob A. Howell, PhD, is a Professor in the Department of Chemistry and Director of the Center for Applications in Polymer Science at Central Michigan University in Mount Pleasant, Michigan. His research interests include the development of nontoxic, environmentally friendly flame retardants based on renewable biosources as well as new polymeric fuel-cell membranes, polymerization techniques, thermal methods of analysis, polymer-supported organoplatinum antitumor agents, and polymers from renewable sources. 

Composite rocket propellants are two-phase mixtures comprising a crystalline oxidizer in a polymeric fuel/binder matrix. The oxidizer... 

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