抄録
Pyrotechnics, which include magnesium powder, produce bright flames, but magnesium is easily aged by water. To prevent the aging problem, which decreases the burning performance and increases the risk of spontaneous combustion, it is necessary to use a stabiliser. In this study, we observed the stabilisation effect of surfactants on the aging of magnesium with ammonium perchlorate and water. The effect of sodium stearate, a straight-chain carboxylate, on the aging of magnesium with ammonium perchlorate and water, was analysed. The results showed an increase in the apparent activation energy of the exothermic reaction of magnesium when sodium stearate was used as a stabiliser. Furthermore, our experiments revealed the stabilising capability of sodium laurate, sodium behenate, and sodium dodecylbenzenesulfonate. But sodium propionate did not exhibit a pronounced stabilisation capability. The experimental results revealed that the stabilisation effect of straight-chain carboxylates increased with increasing length of their hydrocarbon chains. The relationship between the stabilisation effect and the hydrophilic-lipophilic balance was evaluated and revealed that the stabilisation effect of the surfactant on the aging of magnesium with ammonium perchlorate and water depends on its hydrophilicity.
