Investigating the effective parameters on shelf life of Unsymmetrical dimethyl hydrazine

One of the difficulties in the liquid fuels is theirs shelf life. These fuels, like other chemicals, dont meet the military specifications after a period of time due to their destructive reactions. This variation from the specifications, changes the chemical and physical properties of the fuel and its combustion performance. This subject is significant because of the fuel long time storage requirements. Thus, it is necessary to specify, control, and decrease the effective parameters and increase the fuel shelf life. One of the important fuels used in aerospace industries, is unsymmetrical dimethyl hydrazine. Studies show that oxygen, temperature, and storage material of construction are parameters affecting the fuel shelf life. Regarding shelf life conditions, presence of oxygen is the most important parameter affecting the storage shelf life of the fuel. Thus, the effect of oxygen on shelf life of unsymmetrical dimethyl hydrazine was investigated empirically. Results show that the shelf life of this fuel strongly depends on the molecular oxygen. The major products of this oxidation are formaldehyde dimethyl hydrazine, dimethyl amine, ammonia, and water. Assuming the zero and first order reactions, the oxidation rate constants were determined at storage temperature (25 °C) to be 0.021mol.lit-1.min-1 and 0.00023 min-1, respectively.