Kinetics of radical copolymerization of vinylidene fluoride with tert-butyl 2-trifluoromethyl acrylate: a suitable pair for the synthesis of alternating fluorinated copolymers

Abstract

A study of the copolymerization kinetics of vinylidene fluoride with tert-butyl 2-trifluoromethyl acrylate: a suitable pair for the synthesis of alternating fluorinated copolymers.

Synthesis of Vinylidene Fluoride-Based Copolymers Bearing Perfluorinated Ether Pendant Groups and Their Application in Gel Polymer Electrolytes

“…The thermal stabilities of the poly­(VDF- co -MAF-PFE) copolymers were assessed by thermogravimetric analysis (TGA) under air (Figure ). First, a small loss was observed at 140 °C for all polymers because of the degradation of the ester group in the MAF-PFE group, as observed in other poly­(VDF- co -MAF) copolymers ,, where the lower the MAF content the higher the thermal stability of the copolymer. Hence, this loss is steeper for P1 and P2 copolymers (containing 27–28 mol % MAF-PFE) than for P3 possessing 13 mol % (Table ).…”

“…All polymerizations (Table ) were achieved in 1,1,1,3,3-pentafluorobutane as the solvent, , with yields ranging between 23 and 41%. Similar to all MAF esters, which are known not to homopolymerize (reactivity ratio r MAF = r MAF‑TBE = 0), , MAF-PFE behaves the same way.…”

“…The purified poly­(VDF- co -MAF-PFE) copolymers were characterized by 1 H and 19 F NMR spectroscopies (Figures and ). The 1 H NMR spectrum of the poly­(VDF- co -MAF-PFE) P3 copolymer (Figure ) mainly exhibits five characteristic signals: (i) in the 2.3–2.5 ppm range attributed to the reverse (tail-to-tail, T–T) addition of VDF repeat units (−CF 2 CH 2 –CH 2 CF 2 −); − (ii) a signal at 2.9 ppm assigned to the [−CH 2 CF 2 –C H 2 C­(CF 3 )­CO 2 CH 2 R F ]; (iii) a broad one ranging between 2.80 and 3.20 ppm corresponding to normal (head-to-tail, H–T) addition of VDF (−CH 2 CF 2 –CH 2 CF 2 −); − (iv) two multiplets at 4.8 and 5.2 ppm attributed to the two anisochronous protons in −CH 2 C­(CF 3 )­CO 2 C H 2 CF­(CF 3 ) since such a methylene group is adjacent to an asymmetric carbon atom.…”

“…The microstructure of the resulting copolymer was also evidenced by 19 F NMR spectroscopy. For example, Figure displays the 19 F NMR spectrum of the poly­(VDF- co -MAF-PFE) copolymer that mainly exhibits the following characteristic features: (i) a quintet ( 3 J FH = 4 J FF = 10 Hz) centered at −62.7 ppm corresponding to CF 3 from PPFR initiator in −CF 2 –CH 2 –CF 3 as evidence of the regioselectivity of addition of • CF 3 radical onto the less hindered site of VDF; − (ii) a broad signal centered at −70.0 ppm assigned to −CF 3 of H 2 C–C­(CF 3 )– in MAF-PFE units; (iii) signals between −80.0 and −85.0 characteristic of the 13 fluorine atoms in the perfluorinated side chain (−CO–O–CH 2 –CF­(C F 3 )–O–C F 2 –CF­(C F 3 )–O–C F 2 –CF 2 –C F 3 ); (iv) at −92.5 ppm attributed to the normal or head-to-tail (H–T) VDF–VDF dyads (−CH 2 C F 2 –CH 2 CF 2 −) of the PVDF chains; (v) at −96.0 ppm corresponding to the fluorine atoms of the −CF 2 groups of VDF in VDF–MAF-PFE alternating dyads; , (vi) at −114.8 and −117.0 ppm characteristic of the reverse or H–H VDF–VDF dyads (−CH 2 C F 2 –C F 2 CH 2 −); (vii) at −130.5 ppm assigned to both fluorine atoms in −O–CF 2 –C F 2 –CF 3 , (viii) at −134.9 ppm for the F atom in O–CH 2 –C F ­(CF 3 )–; and (viii) at −146.0 for that in −O–CF 2 –C F ­(CF 3 )–.…”

Synthesis, aqueous solution behavior and self-assembly of a dual pH/thermo-responsive fluorinated diblock terpolymer

“…57,58 Therefore, MAF-TBE has only been copolymerized by radical polymerization with various monomers (fluorinated or non-fluorinated). 54,[59][60][61][62] VAc was chosen as a comonomer as its copolymerization with MAF-TBE was shown to result in perfectly alternating copolymers. This alternating structure is due to the high electron-donating character of VAc whereas MAF-TBE is an electron-accepting species.…”