Synthesis and Polymerization of Fluorinated Monomers Bearing a Reactive Lateral Group. 9. Bulk Copolymerization of Vinylidene Fluoride with 4,5,5-Trifluoro-4-ene Pentyl Acetate

Bulk copolymerization of vinylidene fluoride (or 1,1-difluoroethylene (VDF)) with 4,5,5-trifluoro-4-ene pentyl acetate (FAc) initiated by di- tert -butyl peroxide is presented. A series of nine copolymerization reactions was investigated from initial [VDF] 0 /[FAc] 0 molar ratios ranging from 32/68 to 95/5. Both these comonomers copolymerized in this range of copolymerization. Moreover, these comonomers homopolymerized separately in these conditions. The copolymer compositions of these random-type copolymers were calculated by means of 1 H and 19 F NMR spectroscopies and allowed one to quantify the respective amount of each monomeric unit in the copolymer. From the Tidwell and Mortimer method, the reactivity ratios, r i, of both comonomers were determined showing a higher incorporation of FAc in the copolymer ( r FAc = 3.26 ± 1.49 and r VDF = 0.17 ± 0.10 at 120 °C). Alfrey−Price's Q and e values of trifluorovinyl acetoxy monomer FAc were calculated to be 0.060 (from Q VDF = 0.008) or 0.040 (from Q VDF = 0.015) and +1.14 (vs e VDF = 0.40) or +1.23 (vs e VDF = 0.50), respectively, indicating that FAc is an electron-accepting monomer. The normalized monomer-diad and -triad fractions as a function of the polymer composition were obtained from the comonomer sequence distribution theory and this was evidenced by 19 F NMR analysis.