A Study On The Preparation Of Hexafluoropropylene Dimers

This paper mainly studies the dimerization of hexafluoropropylene and the isomerization reaction of D1.The catalyst system of the dimerization of hexafluoropropylene had been studied in this paper。A polar solvent acetonitrile was used as the reaction solvent; KF and crown ether (18-crown-6) was chosen as the catalysts. After the catalyst system determined, the reaction conditions under this system was optimized. The best catalyst ratio of crown ether to KF was1to0.5; the best reaction temperature was30℃considering the energy consumption, and low temperature helped to improve the reaction conversion rate and selectivity; water content within the reaction system should be controlled below50ppm. Under this condition, the conversion rate of hexafluoropropylene was93.79%, and the selectivity of the reaction ws90.96%.As for the isomerization of D1, the best catalyst ratio of crown ether to KF was1to1; the best reaction temperature was60℃; water content within the reaction system also should be controlled below50ppm. Under this condition, the final content of D1in the reaction product was2.00%, and it was91.48%for D2.Then, the kinetics of the dimerization reaction of hexafluoropropylene and the isomerization reaction had been studied in this paper, and the relevant model parameters were determined. Finally, the reactor volume of the isomerization under different reaction conditions was simulated.