Physicochemical\nProperties of Aqueous Film-Forming\nFoams Based on Short Fluorocarbon Surfactant-Graft Hydrophilic Functional\nGroups

The key components of aqueous film foaming foam extinguishing\nagents\nare fluorocarbon surfactants. Due to their toxicity and bioaccumulation,\nlong-chain fluorocarbon surfactants have limited application prospects.\nTherefore, it is of great significance to study short-chain fluorocarbon\nsurfactants as substitutes. In this work, three short-chain fluorocarbon\nsurfactants with various hydrophilic groups and corresponding fire\nextinguishing agents were prepared. The physical and chemical properties\nof a single system and mixed system of fluorocarbon surfactants, including\nsurface activity, spreading property, foaming property, 25% drainage\ntime, and AFFF fire extinguishing property, were studied. For the\nresults of the mixed systems, it was found that the critical micelle\nconcentrations did not exceed 3.97 mmol/L and the minimum surface\ntension did not exceed 17.21 mN/m. Fluorocarbon surfactant solutions\nspread effectively on the surface of all fuels. The foam expansion\nis greater than 7.2, and the shortest of all 25% drainage times is\n3.31 min. The extinguishing time of AFFFs on several fuel fires does\nnot exceed 55 s, and the shortest burn-back time is 15.08 min. Anyways,\nthese results indicate that the grafted hydrophilic short-chain fluorocarbon\nsurfactants have significant application prospects in AFFFs.