Air bag systems

The air bag industry has become one of the principal users of pyrotechnic compositions in the world. Most of the current air bag systems are based on the thermal decomposition of sodium azide, NaN, to rapidly generate a large volume of nitrogen gas, N2. Air bag systems must function immediately (within 50 ms) upon impact, and must quickly deploy a pulse of reasonably cool, nontoxic, unreactive gas to inflate the protective cushion for the driver or passenger. These formulations incorporate an oxidizer such as iron oxide to convert the atomic sodium that initially forms into sodium oxide, Na20. Equation 1 represents the reaction. 

Ion Chromatography has also been utilized for the determination of azide in water effluents and in particulates generated from the deployment of an air bag system. In a recent study (12) particulate material was collected and leached with deionized water. The solutions were then analyzed by Ion Chromatography for anions. A typical chromatogram showing acetate, chloride, nitrite, azide and sulfate is shown in Figure 6. The concentration of azide was also analyzed using a colorimetric technique. Results for equivalent samples correlated to within 5% (12). 

NTO continues to receive attention from both defense and civilian sectors in the USA and other countries as a potential new-generation IHE. It has been used by Navy as an insensitive component to replace RDX as a bomb fill and as a major ingredient by Morton International Inc. to replace sodium azide for the auto air bag system [167]. 

Allen Breed invents the first automotive air bag system... 

The air-bag system, which was developed to reduce cost and increase landing robustness, is designed to provide omnidirectional protection of the payload by bouncing over rocks and other surface hazards. Because the system can also... 

One example of a practical MEMS application is an accelerometer (accelerator/ decelerator sensor) that is used in the deployment of air-bag systems in automobile crashes. For this application, the important microelectronic component is a free-standing microbeam. Compared to conventional air-bag systems, the MEMS units are smaller, lighter, and more reliable and are produced at a considerable cost reduction. 

For reactions involving gases, we can (1) use stoichiometric factors to relate the amount of a gas to amounts of other reactants or products, and (2) use the ideal gas equation to relate the amount of gas to volume, temperature, and pressure. In Example 6-9, we use this approach to determine the volume of N2(g) produced in a typical air-bag system. 

Sodium azide, NaNs, is the nitrogen gas-forming substance used in automobile air-bag systems. It is an ionic compound containing the azide ion, Ns . In this ion, the two nitrogen-to-nitrogen bond lengths are 116 pm. Describe the resonance hybrid Lewis structure of this ion. 

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