Chlorine trifluoride was another of the extremely reactive and toxic oxidisers tested in the United States in the late 1950's. As in the other cases, it was found that the handling problems and safety risks outweighed the performance benefits. ClF3 is available commercially in purities of 99+ per cent ClF3. The most likely impurity is hydrogen fluoride. Chlorine trifluoride is a colorless gas at atmospheric pressure and temperature. The liquid has a pale green colour, while the solid is white. The odour of ClF3 has been described as both sweet and pungent, similar to chlorine or mustard. ClF3 is a toxic and corrosive oxidising agent similar to elemental fluorine in nature. It reacts with water. ClF3 is non-flammable with air, but will support combustion with almost all organic vapours and liquids. ClF3 reacts with every element except the rare gases, nitrogen, and possibly platinum and palladium. However, at low or intermediate temperatures, a protective fluoride film is formed on certain metal surfaces, which halts further reaction. Thus, metals such as mild steel, copper, brass, steel, Monel, and nickel may be used as materials of construction.
Chlorine trifluoride is prepared by direct combination of the elements. The 1959 ClF3 production capacity was 12 to 25 tonnes/year; this could be increased in six to eight months to 50 to 100 tonnes per year by enlarging halogen fluoride reactor capacity without incurring a shortage of fluorine. Quantities in excess of this amount would require a lead time of one year, and would involve construction of new fluorine facilities. The projected price of ClF3 $ 6.00 per kg at the existing rate.
Hydyne was a propellant blend pushed rather vigorously by the Redstone arsenal in the late 1950's, but it found little application. Hydyne, which is also known as MAF-4, is a 60 per cent, by weight, mixture of UDMH and 40 weight percent diethyltrianine (DETA). The normally occurring impurities are dimethylamine, beta-aminoethyl-N-piperazine, and water. Hydyne is a clear, colourless liquid which may become discoloured on exposure to air during storage. Both UDMH and DETA have an ammoniacal odour; the odour is not so sharp or fishy as that of UDMH. Hydyne is a hygroscopic liquid which will absorb carbon dioxide and oxygen from air. It is completely miscible with water and ethanol; the solubility of gasoline and JP-4 in Hydyne are somewhat limited. It forms flammable explosive mixtures with air. Amines generally yellow during storage due to oxidation followed by polymerisation induced by air (O2)· reaction is believed to form an intermediate amine oxide which undergoes polymerisation. The cost of Hydyne in 1959 was $ 0.80 per kg.