| 摘要 |
FIELD: chemistry.SUBSTANCE: present invention relates to a method of producing a fluoropolymer, cyclic fluorine-containing compounds, a fluoropolymer dispersion and a method of extracting a cyclic fluorine-containing compound. The method of producing a fluoropolymer involves water-emulsion polymerisation of one or more fluorinated monomers. Water-emulsion polymerisation is carried out in the presence of at least one cyclic fluorine-containing compound of formula, where X, X, X, identical or different from each other, are independently selected from H, F and C-(per)fluoroalkyl groups, optionally containing one or more oxygen atoms which are included or not included in the chain; L is a bond or divalent group; Ris a divalent fluorinated bridging C-group; Y is a hydrophilic functional group, selected from an anionic functional group of formula, where Xis H, a univalent metal, preferably an alkali metal or an ammonium group of formula -N(R'), where R'is identical or different in each case of use thereof and is a hydrogen atom or a C-hydrocarbon group.EFFECT: obtaining alternative fluorinated surfactants which are used in emulsion polymerisation of fluorinated monomers which exhibit low biological accumulation, lower biological resistance than perfluoroalkane acids having 8 or more carbon atoms.15 cl, 9 dwg, 11 ex |
