Tetrazoles are considered safe and easy-to-handle gas-generating agents. In this study, aminoguanidinium 5,5'-azobis- 1H-tetrazolate (AGAT) was selected as a fuel owing to its high heat of formation and combustibility in an inert atmosphere. Ammonium nitrate (AN) is known as an environmentally friendly oxidizer. However, AN is hygroscopic, which is a problem during manufacturing and storage and when it is mixed with organic fuels that have low burning rates. Despite reports that the stoichiometric AGAT/AN mixture does not burn, this study shows that it is burnable when AN is coated with polyvinyl acetate (ANc). Adding Cu or CuO to the AGAT/ANc mixture increased the burning rate to values comparable to those of the guanidine nitrate/strontium nitrate/basic copper nitrate mixture, a gasgenerating agent used in practical applications. A 4-L tank test was conducted to examine the gas-generating ability of these mixtures. The gas-generating ability was improved to practically relevant values by adding Cu or CuO. To understand the improved burnability of AGAT/ANc, thermogravimetry and differential thermal analyses were performed and the temperature profiles were obtained by means of an embedded K-type thermocouple. Coating with polyvinyl acetate, or adding Cu or CuO, enhanced the decomposition of the mixtures. As the effect of the coating on the thermal decomposition was small, polyvinyl acetate may work as a fuel, and the close contact between AN and the fuel improved the burnability. Using the temperature profiles, the temperature gradients above the burning surface were obtained, indicating that the heat feedback from the gas phase reaction zone controlled the burning rates of the mixtures.
aminoguanidinium 5,5'-azobis-1H-tetrazolate (AGAT), coating ammonium nitrate, combustion, polyvinyl acetate