Otto fuel II
Encyclopedia
Otto fuel II is a monopropellant
used to drive torpedo
es and other weapon systems. It is not related to the Otto cycle
.
(the major component), 2-nitrodiphenylamine
, and dibutyl sebacate
.
It does not need exposure to any oxidant to ignite and release energy, as its three components will react among themselves whenever vaporised and heated. Needing no oxidants and being a stable substance makes Otto fuel ideal for use in the constrained environment of a submarine. Although the fuel can be made to explode, this requires extreme conditions (such that it can be regarded as practically stable). The vapour pressure of the fuel is low (i.e., it is not volatile), minimising toxic hazards. Finally, the fuel's energy density
far surpasses the capacity of the electric battery used in other torpedoes, maximising range.
explosive propellant
propylene glycol dinitrate (PGDN), to which a desensitizer
(dibutyl sebacate) and a stabilizer
(2-nitrodiphenylamine) have been added. The chief
component, propylene glycol dinitrate, accounts for approximately 75% of the mixture, while dibutyl
sebacate and 2-nitrodiphenylamine account for approximately 23% and 2%, respectively.
The principal current use of propylene glycol dinitrate is as a propellant in Otto Fuel II.
Nitrate
s of polyhydric alcohols, of which propylene glycol dinitrate is an example, have been
used in medicine for the treatment of angina pectoris, and as explosives since the mid-nineteenth century.
In addition to its use by the U.S. Navy as a stabilizer in the manufacture of Otto Fuel II,
2-nitrodiphenylamine is employed for similar purposes by the U.S. Army in the manufacture of double base solid propellants. It also has civilian applications as a solvent dye
.
Dibutyl sebacate is a desensitizer in Otto Fuel II. However, its major use is as a plasticizer
in production of plastics, namely cellulose acetate butyrate, cellulose acetate propionate, polyvinyl butyral
, polystyrene
, and many synthetic rubber
s. It can be used for plastics in use in the food packaging
industry. It is also used as a lubricating ingredient
in shaving lotions, and a flavoring additive in non-alcoholic beverages, ice cream
, ices, candy, and baked goods.
One of the products of its combustion is highly toxic hydrogen cyanide gas.
Monopropellant
Monopropellants are propellants composed of chemicals or mixtures of chemicals which can be stored in a single container with some degree of safety. While stable under defined storage conditions, they react very rapidly under certain other conditions to produce a large volume of energetic gases...
used to drive torpedo
Torpedo
The modern torpedo is a self-propelled missile weapon with an explosive warhead, launched above or below the water surface, propelled underwater towards a target, and designed to detonate either on contact with it or in proximity to it.The term torpedo was originally employed for...
es and other weapon systems. It is not related to the Otto cycle
Otto cycle
An Otto cycle is an idealized thermodynamic cycle which describes the functioning of a typical reciprocating piston engine, the thermodynamic cycle most commonly found in automobile engines....
.
Properties
This distinct-smelling, reddish-orange, oily liquid is a mixture of three synthetic substances: propylene glycol dinitratePropylene glycol dinitrate
Propylene glycol dinitrate is an organic chemical, an ester of nitric acid and propylene glycol. It is structurally similar to nitroglycerin, except that it has one fewer -O-NO2 group...
(the major component), 2-nitrodiphenylamine
2-Nitrodiphenylamine
2-Nitrodiphenylamine, also called NDPA, 2-NDPA, 2NO2DPA, Sudan Yellow 1339, C.I. 10335, CI 10335, phenyl 2-nitrophenylamine, 2-nitro-N-phenylaniline, or N-phenyl-o-nitroaniline, is an organic chemical, a nitrated aromatic amine, a derivate of diphenylamine. Its chemical formula is C12H10N2O2, or...
, and dibutyl sebacate
Dibutyl sebacate
Dibutyl sebacate is an organic chemical, a dibutyl ester of sebacic acid. Its main use is as a plasticizer in production of plastics, namely cellulose acetate butyrate, cellulose acetate propionate, ethyl cellulose, polyvinyl butyral, polyvinyl chloride, polystyrene, and many synthetic rubbers ...
.
It does not need exposure to any oxidant to ignite and release energy, as its three components will react among themselves whenever vaporised and heated. Needing no oxidants and being a stable substance makes Otto fuel ideal for use in the constrained environment of a submarine. Although the fuel can be made to explode, this requires extreme conditions (such that it can be regarded as practically stable). The vapour pressure of the fuel is low (i.e., it is not volatile), minimising toxic hazards. Finally, the fuel's energy density
Energy density
Energy density is a term used for the amount of energy stored in a given system or region of space per unit volume. Often only the useful or extractable energy is quantified, which is to say that chemically inaccessible energy such as rest mass energy is ignored...
far surpasses the capacity of the electric battery used in other torpedoes, maximising range.
Major ingredients
Named after its inventor, Dr Otto Reitlinger, Otto Fuel II consists of the nitrated esterEster
Esters are chemical compounds derived by reacting an oxoacid with a hydroxyl compound such as an alcohol or phenol. Esters are usually derived from an inorganic acid or organic acid in which at least one -OH group is replaced by an -O-alkyl group, and most commonly from carboxylic acids and...
explosive propellant
Propellant
A propellant is a material that produces pressurized gas that:* can be directed through a nozzle, thereby producing thrust ;...
propylene glycol dinitrate (PGDN), to which a desensitizer
Phlegmatized
Phlegmatized is a term applied to an explosive that has had an agent added to stabilize or desensitize it. Sometimes this is desirable, to enable handling or to reduce the rate of combustion. Typical phlegmatizing agents include wax, paper, water, and paraffin. These agents are nearly always...
(dibutyl sebacate) and a stabilizer
Stabilizer (chemistry)
In chemistry a stabilizer is a chemical which tends to inhibit the reaction between two or more other chemicals. It can be thought of as the antonym to a catalyst...
(2-nitrodiphenylamine) have been added. The chief
component, propylene glycol dinitrate, accounts for approximately 75% of the mixture, while dibutyl
sebacate and 2-nitrodiphenylamine account for approximately 23% and 2%, respectively.
The principal current use of propylene glycol dinitrate is as a propellant in Otto Fuel II.
Nitrate
Nitrate
The nitrate ion is a polyatomic ion with the molecular formula NO and a molecular mass of 62.0049 g/mol. It is the conjugate base of nitric acid, consisting of one central nitrogen atom surrounded by three identically-bonded oxygen atoms in a trigonal planar arrangement. The nitrate ion carries a...
s of polyhydric alcohols, of which propylene glycol dinitrate is an example, have been
used in medicine for the treatment of angina pectoris, and as explosives since the mid-nineteenth century.
In addition to its use by the U.S. Navy as a stabilizer in the manufacture of Otto Fuel II,
2-nitrodiphenylamine is employed for similar purposes by the U.S. Army in the manufacture of double base solid propellants. It also has civilian applications as a solvent dye
Solvent dye
A solvent dye is a dye soluble in organic solvents. It is usually used as a solution in an organic solvent. Solvent dyes are used to color organic solvents, hydrocarbon fuels, waxes, lubricants, plastics, and other hydrocarbon-based nonpolar materials. Fuel dyes are one use of solvent dyes. Their...
.
Dibutyl sebacate is a desensitizer in Otto Fuel II. However, its major use is as a plasticizer
Plasticizer
Plasticizers or dispersants are additives that increase the plasticity or fluidity of the material to which they are added; these include plastics, cement, concrete, wallboard, and clay. Although the same compounds are often used for both plastics and concretes the desired effects and results are...
in production of plastics, namely cellulose acetate butyrate, cellulose acetate propionate, polyvinyl butyral
Polyvinyl butyral
Polyvinyl butyral is a resin usually used for applications that require strong binding, optical clarity, adhesion to many surfaces, toughness and flexibility. It is prepared from polyvinyl alcohol by reaction with butyraldehyde. The major application is laminated safety glass for automobile...
, polystyrene
Polystyrene
Polystyrene ) also known as Thermocole, abbreviated following ISO Standard PS, is an aromatic polymer made from the monomer styrene, a liquid hydrocarbon that is manufactured from petroleum by the chemical industry...
, and many synthetic rubber
Synthetic rubber
Synthetic rubber is is any type of artificial elastomer, invariably a polymer. An elastomer is a material with the mechanical property that it can undergo much more elastic deformation under stress than most materials and still return to its previous size without permanent deformation...
s. It can be used for plastics in use in the food packaging
Packaging and labelling
Packaging is the science, art, and technology of enclosing or protecting products for distribution, storage, sale, and use. Packaging also refers to the process of design, evaluation, and production of packages. Packaging can be described as a coordinated system of preparing goods for transport,...
industry. It is also used as a lubricating ingredient
Lubricant
A lubricant is a substance introduced to reduce friction between moving surfaces. It may also have the function of transporting foreign particles and of distributing heat...
in shaving lotions, and a flavoring additive in non-alcoholic beverages, ice cream
Ice cream
Ice cream is a frozen dessert usually made from dairy products, such as milk and cream, and often combined with fruits or other ingredients and flavours. Most varieties contain sugar, although some are made with other sweeteners...
, ices, candy, and baked goods.
Toxicity
Otto fuel II is a toxic substance found in EPA's National Priorities List. Ingestion of contaminated food or direct exposure at worksites can cause headaches, poor eye–hand coordination, eye irritation, congested noses, nausea, dizziness, and difficulty breathing. No fatal cases of overexposure have yet been reported.One of the products of its combustion is highly toxic hydrogen cyanide gas.