Synthesis method of low-carbon-chain perfluoroalkyl iodine

The invention discloses a synthesis method of low-carbon-chain perfluoroalkyl iodine. The synthesis method includes the steps of: continuously feeding pentafluoroethane, iodine vapor, tetrafluoroethylene and a fluorine/nitrogen gas mixture together into a tubular reactor to perform a reaction to produce a gas mixture; and alkaline-washing, drying and separating the gas mixture to prepare a mixtureof various perfluoroalkyl iodine products. In the method, molar ratio of the pentafluoroethane to the iodine vapor is 1:1-2; the molar ratio of the pentafluoroethane to the tetrafluoroethylene is 1:5-20; the molar ratio of the pentafluoroethane to the fluorine gas in the fluorine/nitrogen gas mixture is 1:0.001-1:0.01. Reaction temperature is 250-380 DEG C and reaction retention time is 1-15 s. The method has simple processes and high efficiency, is safe and controllable, and has good product component distribution. 本发明公开了种低碳链全氟烷基碘的合成方法，将五氟乙烷、碘蒸气、四氟乙烯、氟氮混合气起连续通入管式反应器中进行反应，反应所得混合气经碱洗，干燥，分离得到多种全氟烷基碘产品的混合物，所述五氟乙烷与碘蒸气的摩尔