Study On Synthesis And Properties Of Novel Fluorinated Surfactants

Fluorinated surfactant is a kind of special surfactant which usually has high surface activity,high chemical stability,high thermal stability,with its fluorocarbon chain both hydrophobic and oleophobic.Because of its excellent properties,it has been used in many occasions that traditional hydrocarbon surfactant difficult to be qualified,and widely broadened the application areas of surfactants.But actually the most widely used fluorinated surfactants,which means perfluorooctane sulfonic acid(PFOS),pentadecafluorooctanoic acid(PFOA)and their potential precursors,have been exposed highly persistent and bioaccumulative,and have been detected ubiquitously in the abiotic environment,biota,food items and humans in recent years.They have been listed in the organic pollutants which are the most difficult to be degraded,limited even prohibited by lots of states and organizations,just because of their long fluorocarbon chains.So,to synthesize novel fluorinated surfactants with short fluorocarbon chains,good properties and environment-friendly has been one of the hotspots in the synthetic research area of fluorinated surfactants.In this thesis,different kinds of fluorinated surfactants were designed and synthesized with molecular designing idea,that is,starting with perfluoroalkyl componds with short fluorocarbon chains,such as 2-(perfluorohexyl)ethyl alcohol or nonafluoro-1-iodobutane as main raw materials.The main contents are as follows:1.Introductions of fluorinated surfactants,classifications,synthesis methods,main applications,recent researches.2.2-(Perfluorohexyl)ethyl alcohol was oxidated to 2-(perfluorohexyl)ethanoic acid with two oxidation methods,then chlorinated to 2-(perfluorohexyl)ethanoyl chloride with thionyl chloride.Amides were synthesized from 2-(perfluorohexyl)ethanoyl chloride with 3-dimethylaminopropylamine by amidation reaction.At last,three kinds of single chain fluorinated surfactants were prepared by quaternarization,with the structures characterized by IR,1H NMR,19F NMR,13C NMR.3.P-phthalic acid was chlorinated to prepare diacyl chloride.Different amides were synthesized from the diacyl chloride with N,N-dimethylethylenediamine,N,N-diethylethylenediamine,3-diethylaminopropylamine,3-dimethylaminopropylamine by amidation reaction,then reacted with nonafluoro-l-iodobutane by quaternarization.Different kinds of Gemini fluorinated surfactants were prepared,with the structures characterized by IR,1H NMR,19F NMR,13C NMR.The influences of amidation reaction and quaternarization were studied and the best reaction condition were reached.4.The properties such as surface tention,thermal stability,foam property,emulsifying property of the synthesized fluorinated surfactants were studied.