PREPARATION METHOD FOR HEXAFLUOROBUTADIENE

The present invention relates to a preparation method for hexafluorobutadiene. The method comprises: 1) performing temperature raising and pressure increase reactions on chlorotrifluoroethylene, and then performing a thermal polymerization reaction on same to obtain a precursor; 2) performing fractional distillation on the precursor and obtaining a low-boiling-point intermediate, and recovering a residual solution; 3) adding the intermediate into ethanol, performing a reflux reaction under a zinc catalyst to collect a gas product, and then mixing the collected gas product with hydrogen iodide, performing high-temperature ring opening, and performing condensation recovery to obtain a condensate solution; and 4) mixing the condensate solution with the residual solution in step 2), reacting with chlorine water under photocatalysis, adding the mixture into diethylene glycol monobutyl ether, performing a heating reaction under a zinc catalyst, performing condensation reflux to remove impurities, and enabling the g