Preparation of novel gel foam and its fire suppression performance against gasoline pool fires

The phenomenon of re-ignition after extinguishing tank fires poses a significant challenge for firefighting and rescue operations. In this study, a gel foam was prepared using linseed gum as the gelling agent and sodium tetraborate as the cross-linking agent. By analyzing the foaming performance of the gel foam, the optimal formulation for the gel foam was determined. Subsequently, microscopic structural observations and thermal stability tests were conducted on this material. A comparison of the firefighting performance between the gel foam and aqueous film-forming foam (AFFF) on extinguishing gasoline pool fires was also carried out. The results indicate when the foaming agent, consisting of coconut oil glucoside (APG0814) and fatty alcohol polyoxyethylene ether (AEO-9), is used in a 9:1 ratio with a mass fraction of 0.4 wt%. Furthermore, by introducing 0.35 wt% concentration of linseed gum and 0.02 wt% concentration of sodium tetraborate, the gel foam exhibits a foaming expansion ratio of 6.5, a half-life of 203 min, and a comprehensive value of 989.63, which represents the best performance. The gel foam and the AFFF exhibit relatively similar extinguishing effectiveness, with respective extinguishing times of 108s and 95s. Further analysis of the gel foam's resistance to re-ignition reveals that the gel foam demonstrates 25 % and 90 % ignition resistance times of 425s and 573s, respectively, representing a significant enhancement of 66.02 % and 104.64 % compared to the AFFF. These results indicate that the novel gel foam possesses excellent resistance to re-ignition, reducing the risk of fire rekindling in liquid fire scenarios. This research serves as a valuable reference for the development of environmentally friendly and re-ignition-resistant gel foam for extinguishing liquid fires.