Preparation And Application Of Fluorocarbon Surfactant Based On Perfluorobutyl

Aqueous film-forming foam fire extinguishing agent(AFFF)is a highly effective extinguishing agent recommended by ICAO for extinguishing aircraft and aviation fuel fires.Because its core components are organic pollutants,it is listed in the prohibition list by international conventions.In order to solve the problem of environmental pollution caused by PFOS and its derivatives,a non-toxic and non-polluting short carbon chain fluorocarbon surfactant was prepared by synthetic technology.In this study,a short carbon chain fire extinguishing agent was prepared and its fire extinguishing performance was tested.Firstly,in the preparation of short carbon chain fluorocarbon surfactant,perfluorobutyl sulfonyl fluoride is used as raw material to react with bromoethanol and iodomethane respectively to prepare bromine-containing fluorocarbon surfactant(FC4-Br)and iodinecontaining fluorocarbon surfactant(FC4-I).The surface tension of FC4-Br is as low as 17.05 mN/m and the critical micelle concentration(cmc)is 1.12%.The foaming times can reach 5 times and the 25% liquid separation time is close to 3 minutes when it is prepared into 1% water solution.The surface tension of FC4-I is as low as 18.59 mN/m and the critical micelle concentration is 1.35%.It is formulated into an aqueous solution having a concentration of 1%,which hardly foamed,and the 25% liquid separation time is also short.Considering the surface properties and foaming properties,FC4-Br was selected as the compounding agent for compounding with hydrocarbon surfactant in this study.The second point is the compounding of short carbon chain fluorocarbon surfactants.FC4-Br was compounded with butanesulfonic acid sodium salt,sodium hexane sulfonate and sodium octane sulfonate respectively,and the surface properties,spreading properties and foaming properties of the three mixed solutions were tested.It was found that FC4-Br and sodium hexane sulfonate had the best compounding effect.After compounding,the surface tension and critical micelle concentration of the mixed solution decreased to 16.62 mN/m and 0.41%,respectively.Fast spreading can be realized on cyclohexane,aviation fuel and 95 # gasoline.When the concentration of the mixed solution of FC4-Br and sodium hexane sulfonate is 1%,the foaming multiple can reach 7.4 times and the 25% liquid separation time is 372 s.Finally,in the preparation of short carbon chain fluorocarbon surfactant extinguishing agent,the compound solution of FC4-Br and sodium hexane sulfonate is taken as the base solution,and additives such as amphiprotic surfactant BS-12,Sodium alpha-olefin Sulfonate and xanthan gum are sequentially added to prepare mixed solutions with different concentrations,and then parameters such as foaming times,liquid separation time and the like of the mixed solution are tested.The optimum mass fraction of amphiprotic surfactant BS-12,alpha-olefin sulfonate and xanthan gum were determined to be 0.36%,0.18% and 0.012%,respectively.Then diethylene glycol butyl ether,ethylene glycol,urea and the like are selected as auxiliary reagents to be added into the mixed solution to prepare foam extinguishing agent concentrated solution.The concentrated solution was added into tap water to prepare 6% water film-forming foam extinguishing agent.The fire extinguishing experiment was carried out according to the requirements of national standard GB 15308-2006.It was found that the fire extinguishing time was less than 1min and the fire resistance time was more than 14 min,which met the requirements of national standard Ⅰ A level.To sum up,the new surfactant in this study not only has good environmental protection performance,but also has excellent deactivation performance,and has the potential to be used as a new generation of environmentally friendly water film-forming foam extinguishing agent surfactant.