Gas generators for airbag inflation became a standard equipment of cars and improved safety of drivers and passengers substantially. In case of an accident there is still an additional risk that fire might arise - especially in the engine room - endangering driver and passengers. Recently, systematic investigations started to realise the idea of using gases or aerosols produced by solid energetic or pyrotechnique materials - similar to airbag technology - for fire extinguishing in cars. The actually introduced chemical gas generator formulations are based on the experience of pyrotechnics and solid propellants. Sodium aside and nitrocellulose containing mixtures cover most applications of mass production. Despite their high level of technical development, both formulations exhibit strong disadvantages. The work reported considers organic formulations for fire extinguishing, which produce gases composed of N2 and CO2. The gas generants described consist of non-toxic chemicals including fuel, oxidant, catalyst and cooling agent for thermal process control. The formulations show higher gas output per mass, can be recycled environmentally friendly and are of low costs. The results comprise thermochemical properties governing the time dependent gas output, characterisation of the constituents and trace species of the product gas, safety and stability aspects. From selected gas generants, the following data were measured: (1) Estimation of thermal stability using DSC methods and mass-loss tests; (2) Pressure/time curves in the ballistic bomb; and (3) Rate of product gases by means of gas chromatography. For the covering abstract see ITRD E116488.
Abstract