Telomers of 1, 1, 3, 3, 3-pentafluoropropylene. (December 2015) - Boschet, Frédéric
Graphical abstract: Highlights: Original highly fluorinated 1, 1, 3, 3, 3-pentafluoropropylene (PFP) telomers. (Co)telomers containing PFP, vinylidene fluoride, 3, 3, 3-trifluoropropene, and tert -butyl-α-trifluoromethylacrylate. NMR characterization gives full evidence of structures. Low molecular weights of the (co)telomers. Poor reactivity of PFP. Abstract: The synthesis of original highly fluorinated telomers containing 1, 1, 3, 3, 3-pentafluoropropylene (PFP, R1225ze), RF (C3 HF5 ) n I [where n stands for 1 and 2 and RF corresponds to either C6 F13 or (CF3 )2 CF] and their cotelomers of general formula: RF {[F2 CCH(CF3 )] x − (CH2 CR1 R2 ) y } z I, based on vinylidene fluoride H2 CCF2 (VDF) (R1 R2 F); 3, 3, 3-trifluoropropene, CH2 CHCF3, (TFP) (R1 H, R2 CF3 ), and tert -butyl 2-trifluoromethylacrylate (TFMA) (R1 CF3, R2 CO2 tert -Bu) are presented. These (co)telomers were obtained from thermal initiation or in the presence of peroxides, in bulk and in solution (1, 1, 1, 3, 3-pentafluorobutane), leading to monoadduct and diadduct, the amounts of which depending upon the [RF I]0 /[PFP]0 initial molar ratio ( R 0 ). The percentage of monoadduct increased up to 50–60% versus dimer (30–25%) at temperatures up to 143 °C with peroxides as the initiator (In) and initial c 0 = [In]0 /[∑(Monomers)]0 molar ratios up to a degree of telomerization of 1.5. All the synthesized (co)telomers were characterized by 1 H and 19 F NMR spectroscopies and evidenced isomers. The molecular weights, ranging between 430 and 1500 g mol −1 and molecular weight distributions were assessed by GPC (SEC) chromatography and NMR.