Syntheses And Properties Of Organic Compounds Bearing Short Perfluoroalkyl Chains

Fluorinated organic componds(FOCs)are widely used in aerospace,pharmaceuticals,chemicals,pesticides and so on.,because of their excellent performance.Currently many used fluorinated organic componds usually are composed of long perfluoroalkyl chains,which have been found to pose high environmental and biological accumulation and potential high toxicity to human and wildlife health.To relieve this problem,developing fluorinated organic componds with short perfluoroalkyl chains is necessary.In this thesis,short fluorocarbon chain containing compounds,such as perfluorobutane-l-sulfonyl fluoride,perfluorohexane-l-sulfonyl fluoride and trifluoro methanesulfonic acid,are used as start materials,and the design and syntheses of three types of fluorinated organic componds are achieved.This thesis is consisted of the following five parts.1.The types and applications of fluorinated organic componds as well as the syntheses of fluorine-containing precursor materials are summarized.Meanwhile,the development trend of fluorinated organic compounds is outlined.The research plan of this thesis is described.2.Starting with short fluorocarbon chain-containing precursor materials,such as perfluorobutane-l-sulfonyl fluoride,perfluorohexane-l-sulfonyl fluoride and trifluoromethane sulfonic acid,a series of bis(perfluoroalkylsulfonyl)imide salts were synthesized.The thermal stability of these compounds was studied by TG and the results show that these compounds have good thermal stability.The reaction conditions for the scale-up synthesis of lithium bis(trifluoromethylsulfonyl)imide were otimized and a total yield of 67%for the target compound was achieved.These compounds are expected to be useful in the fields of battery materials,catalytic reaction and ion exchanges,etc.3.Starting with short fluorocarbon chain-containing precursor materials,such as perfluorobutane-1-sulfonyl fluoride,perfluorohexane-1-sulfonyl fluoride,four classes of new surfactants,namely perfluoroalkylsulfonyloxybenzyl cationic surfactants,perfluoroalkylsulfonyloxyphenyl amine oxide surfactants,perfluorohexylsulfonyloxy benzyl amphoteric surfactants and perfluoroalkyl containing anion surfactants,were designed and synthesized.The surface properties of these surfactants were evaluated by surface tension measurements.The results show that the surface tensions of most of these fluorinated surfactants are around 20 mN m-1,some of the them are less than 18 mN m-1,and the critical micelle concentration values are around 1.0×10-4 mol L-1,displaying excellent surface activities.The thermal stability of these compounds was studied by TG measurements and the results show that these compounds have excellent thermal stability.4.In an application study of the compounds synthesized as above,one compound was chosen as an effective component for the formulation of a series of aqueous film-forming foam extinguishing agents.The effects of foaming agents,thickeners and other ingredients of aqueous film-forming foam extinguishing agent were studied.For an aqueous film-forming foam extinguishing agent with optimized formulation,its performance was tested for oil fire fighting,and the result show that the aqueous film-forming foam extinguishing agent has an excellent performance with a set of critical parameters higher than the national standards.5.Starting with the short fluorocarbon chain-containing precursor materials including perfluorobutane-l-sulfonyl fluoride,perfluorohexane-l-sulfonyl fluoride,nine gemini perfluoroalkylsulfonyloxybenzyl cationic surfactants were synthesized.The surface properties of these surfactants were evaluated by surface tension.The results show that the surface tensions of most of these fluorinated surfactants are around 20～30 mN m-1,and the critical micelle concentration values are around 1.0×10-4 mol L-1.A lowest surface tension of 20.7 mN m-1 and a lowest critical micellar concentration of 0.17 mM were observed for the gemini perfluorobutylsulfonyloxybenzyl cationic surfactants with the spacer lengths of n=2 and n=6,respectively.The aggregate morphologies of these surfactants formed in water were studied and the surfactant with the spacer lengths of n=2 formed rod-like micelles whereas the surfactants with the spacer lengths of n=3,4,6 formed spherical micelles.The thermal stability of these compounds was studied by TG and the results show that these compounds have good thermal stability.The antimicrobial activities of these gemini nonafluorobutanesulfonylbenzyl cationic surfactants were tested and the results show that these compounds have some antibacterial activity.