Jetex Archive: Motors


	the Classic Jetex archive
		MOTORS

		Fuel for Jetex motors

Jetex motor fuel

Above: Perhaps the best-known container of Jetex fuel was the yellow Sebel tin of 20 Jetex 50 pellets.
Right: American Telasco produced V-Max fuel .

The first Jetex fuel was produced by Imperial Chemical Industries, in Scotland, and was based on guanidine nitrate oxidizer used with nitrated resorcinols. Over the years other companies have also made a variety of Jetex-type fuels, under various names, and with varying levels of performance.

Below, we give details of the main constituent, guanidine nitrate, and related chemical structures.

Guanidine nitrate (GN, NH:C(NH2)2. HNO3).

MP: 215-216ºC
Molecular weight: 122.1
White or creamy grain or crystal
Applications: raw material for production of medicines, explosives, coatings, dyes.

Readily soluble in alcohol, very readily in water, and may be recrystallized from either solvent.

Traditionally, Jetex fuel has used this organic oxidizer, which sometimes comprises more than 90% of the pellet weight. GN is especially useful as a gas-generating chemical since it is entirely comprised of gaseous elements and carbon. This permits it to burn without ash, slag, or residue.

Further, GN propellants decompose at a rather low temperature. It appears that in decomposition, nitrous oxide and a small amount of nitrogen are first produced. CO2 comes off later and more slowly. NH3 is apparently also expelled. The final products of combustion are probably CO2, water, CO, and nitrogen.

GN is essentially a compound comprised of guanidine (NH2--C(NH)--NH2 and nitric acid (HNO3) radicals. Structurally, GN is 2NH2--C(NH)--NH2.HNO3. Each molecule has two molecules of guanidine combined with one molecule of nitric acid. From this it is apparent that GN differs chemically from the inorganic nitrates, such as KNO3 and AN.

Guanidine itself is crystalline, deliquescent, and strongly caustic, taking up CO2 from the air. It is a strong monoacid base, indistinguishable from KOH in an electrometric titration. It was first obtained by the oxidation of guanine. This is a substance found in guano and closely related to uric acid; it is interesting to note that the saltpeter [KNO3 and NaNO3] deposits of history were also associated with guano deposits, often within caves. In modern use, cyanamide (NH2--C--N), a widely used organic precursor, can be used to synthesize guanidine. Cyanamide is produced from coke, limestone, and nitrogen gas.

Guanidine nitrate can be synthesized from dicyandiamide by the action of aqua regia (a process patented in 1909). More commonly, it is synthesized from dicyandiamide and ammonium nitrate (AN).

Chemical Structures

Packing from a Jetex Red Spot carton of 100/Jetmaster pellets

Acknowledgements

Illustration sources:
- Chemical structures: Original diagrams by Carlo Godel
- Red Spot pack: photograph by Peter Lloyd

Queries? Corrections? Additions? .