DEVELOPMENT AND CHARACTERIZATION OF NON-AZIDE AUTOMOTIVE AIRBAG GENERANT SYSTEMS

摘要

Sodium azide based automotive airbag gas generants have been shown to be environmentally unfriendly. Azides from airbag production facilities and scrapped automobiles may contaminate soil and ground water. Non-azide pyrotechnic airbag systems are one solution to this problem. Initial Talley pyrotechnic formulations were far less toxic than azide systems, but had performance issues. These issues included high operating pressures, ignition difficulties, performance variability and detonability of main generant. A series of main generant/enhancer combinations were formulated which resolved most of these issues, although still required high (27 to 62 megapascals) operating pressures. Because of the pressure requirements, these Talley systems require an ignition enhancer. The current Talley main automotive airbag gas generant is a guanidine nitrate, ammonium perchlorate and sodium nitrate based composition. The current ignition enhancer is based on the same three ingredients with the addition of RDX. These compositions are used in Talley's D60 automotive airbag inflators. A brief discussion of the problems associated with azide based systems will be presented. The properties and formulations of the pyrotechnic generant and ignition enhancer compositions will be presented, along with their development history. Inflator development will be briefly examined. General methods of ingredient and formulation preparation will be given. Characterization data, such as selected chemical, physical, mechanical and ballistic properties will be presented. The effects on performance of aging these compositions in various environments will be examined. The results of hazards testing (friction, impact, electrostatic, detonation etc.) will be presented. Acceptance criteria and performance testing will be described and the results will be discussed.