Optimization and Performance Evaluation of an Environmentally Friendly Fluorine-Free Foam Extinguishing Agent

Fluorine-free foam fire extinguishing agents are environmentally friendly compared with aqueous film-forming foam fire extinguishing agents (AFFF). Design-Expert 11.0 software and the Box-Behnken design principle were used to optimize the foaming agent formulation which is the core of fluorine-free foam extinguishing agents and regression models of the expansion ratio ( α ), 50% drainage time ( t 50%) and surface tension ( γ ) were established. Furthermore, the optimal combination of foaming agent various factors (the mass fraction of APG0810, silicone surfactant, SDS and BS-12) were predicted by the regression models. The prediction results showed that when the mass fraction of APG0810, silicone surfactant, SDS and BS-12 were 2.0%, 0.242%, 0.116% and 0.349%, respectively, the comprehensive foaming agent performance was highest. The α , t 50% and γ of the optimized foaming agent were 8.0, 376 s, and 24.1 mN/m, respectively. The fluorinefree foam fire extinguishing agent was prepared by compounding the optimized foaming agent with foam stabilizers and other additives, resulting in a surface tension of 24.3 mN/m and a spreading factor greater than zero. The, α , t 50% and sealing time of the fluorine-free foam fire extinguishing agent were 7.6, 541 s, and 895 s, respectively, which were 8.6%, 16.1%, and 14% higher than commercial 6% AFFF.