Surface modification of sodium bicarbonate ultrafine powder extinguishing agent by environmental friendly fluorinated acrylate copolymers

Common ultrafine powder fire extinguishing agent couldn't put out the oil fire. To solve this problem, a simple and controllable way for preparing hydrophobic and oleophobic fire extinguishing agent was developed. Firstly, fluorinated acrylate copolymers (FP) with different fluorine contents were prepared and used to modify the extinguishing agent. Unlike perfluorooctane sulphonate/perfluorooctanoic acids (PFOS/PFOA) with C8-fluorocarbon chains widely used as modifiers, the prepared FP with C6-fluorocarbon chains not only met the environmental standards, but also possessed excellent properties. Subsequently, the fluorine contents of particles modified by two FP were 19.3% and 37.4% respectively. The contact angles of deionized water were 103.5 degrees and 117 degrees respectively, and those of aviation kerosene were 68 degrees and 120.5 degrees respectively. They possessed outstanding hydrophobicity, but particles modified by FP2 had better oleophobicity. Finally, the particles covered the surface of fuel, which prevented the fuel from evaporating. Combined with the effect of interrupting the combustion chain reaction, the flame was gradually extinguished. (C) 2021 Elsevier Ltd. All rights reserved.