| 摘要 |
The invention comprises perfluorolefin epoxide polyethers of general formula X-CF2-CF2-O-[-CF(X)-CF2-O-]-nCF2-X where n is at least 8 and X is fluorine or a perfluoromethyl radical. They are prepared by heating a perfluorinated acid of general formula <FORM:1000802/C3/1> with fluorine at 50-300 DEG C. The perfluorinated acid is prepared by hydrolysis of the polymers of hexafluoropropylene and tetrafluoroethylene epoxides obtained by treating the monomer in a nitrogen atmosphere in presence of carbon at room temperature for 3 days after which various fractions are obtained by distillation, e.g. of hexafluoropropylene to yield fractions where n=0, 1, 2-35 and >35. Hydrolysis takes place by contacting the polymer as such or in solution in a perfluorinated saturated hydrocarbon, with water. Decarbonylation and fluorination is effected by passing fluorine which may be diluted with inert gases, e.g. nitrogen, helium or argon through the liquid polymer or a solution thereof in an inert solvent at 50-300 DEG C. Suitable solvents are perfluoroheptane, perfluorodimethyl cyclo-butane, perfluorocyclohexane and perfluorokerosenes. Examples describe the preparation of perfluoroolefin epoxide polyethers, where n is 8-11, X is CF3; n is >35, X is CF3; n is 1, X is CF3; and perfluorinated tetraethylene epoxide polyethers of average M.W.=1000.ALSO:The invention comprises perfluoro-olefin epoxide polyethers of general formula <FORM:1000802/C2/1> where n is 0 or an integer and X is fluorine or a perfluoromethyl radical. They are prepared by heating a perfluorinated acid of general formula <FORM:1000802/C2/2> where n is 0 or an integer and X is fluorine or a perfluoromethyl radical, with fluorine at 50-300 DEG C. The perfluorinated acid is prepared by hydrolysis of the reaction product obtained by treating monomer hexafluoropropylene or tetrafluoroethylene epoxide in a nitrogen atmosphere in presence of carbon at room temperature for 3 days after which various fractions are obtained by distillation, e.g. of hexafluoropropylene epoxide to yield fractions where n = 0, 1, 2-35 and >35. Hydrolysis takes place by contacting the polymer as such or in solution in a perfluorinated saturated hydrocarbon, with water. Decarboxylation and fluorination is effected by passing fluorine which may be diluted with inert gases e.g. nitrogen, helium or argon through the liquid polymer or a solution thereof in an inert solvent at 50-300 DEG C. Suitable solvents are perfluoroheptane, perfluorodimethylcyclobutane, perfluorocyclohexane and perfluorokerosenes. Examples describe the preparation of perfluoro olefin epoxide polyethers where n is 8-11, X is CF3; n is >35, X is CF3; n is 1, X is CF3; and perfluoroinated tetramethylene epoxide polyethers of average M.W. = 1000. Example 3 describes the preparation of 1 - (pentafluoroethoxy) - 2 - (heptafluoropropoxy)hexafluoropropane. |
