Burning Rate Characterization of Guanidine Nitrate and Basic Copper Nitrate Gas Generants with Metal Oxide Additives

Automotive airbag gas generants have been studied extensively to meet design and safety requirements. Additives have historically been used to increase their burning rates, but the effects of additive size have not been thoroughly investigated. The current study evaluated the effects of nano- and micro-sized metal oxides on the combustion of guanidine nitrate (GN) and basic copper nitrate (BCN) gas generant systems. Three metal oxide additives were chosen for this study: alumina (Al2O3), ceria (CeO2), and titania (TiO2). Nano- and micro-sized particles were incorporated into gas generants at a mass loading of 4%. Cylindrical pellets with and without additive particles were manufactured, and their homogeneity was confirmed through scanning electron microscopy analyses. Pellets were burned over a range of pressures from 6.9 MPa (1,000 psi) to 27.6 MPa (4,000 psi). Micro-ceria was the only additive observed to enhance the burning rate relative to the baseline.

Automated summary

This study evaluated the effects of nano- and micro-sized metal oxides on the combustion of automotive airbag gas generant systems, with micro-ceria observed as the only additive that enhanced the burning rate.