Superior Thermostability and Hydrophobicity of Poly(vinylidene fluoride-co-fluoroalkyl 2-trifluoromethacrylate)

Abstract

tridecafluorooctyl 2-(trifluoromethyl)acrylate (MAF-C 6 F 13 ) was synthesized and copolymerized with vinylidene fluoride (VDF). First, the preparation of MAF-C 6 F 13 was achieved by two different routes: (i) transesterification of tert-butyl 2-trifluoromethacrylate (MAF-tBu) with C 6 F 13 C 2 H 4 OH (55% yield with ∼95% purity) and (ii) esterification of 2trifluoromethacryloyl chloride with the same fluorinated alcohol, which gave higher yield (82%) and purity (99%). The radical copolymerization of MAF-C 6 F 13 with VDF was initiated by three different systems (two peroxypivalates and one highly branched fluorinated persistent radical, PPFR), a chain transfer agent (CF 3 I), at various polymerization temperatures (65−90 °C) and in three types of solvents. The relative comonomer incorporation and number-average molecular weights (M n s) of the resulting random poly(VDF-co-MAF-C 6 F 13 ) copolymers were assessed by NMR spectroscopy. Both features alongwith polymerization yields were influenced by the polymerization temperatures and the nature of solvents. The M n values were further affected by the type of initiators and the use of chain transfer agent. When dimethyl carbonate was used as the solvent, lower (2−4 mol %) MAF-C 6 F 13 comonomer was incorporated compared to those reactions that involved 1,1,1,3,3-pentafluorobutane (5−33 mol %). Surprisingly, M n s of these copolymers increased with polymerization temperatures when the reactions were initiated by PPFR. Thus, the copolymerization carried out at 65 °C and initiated by PPFR led to a M n of 33 000 g mol −1 , while those achieved at 90 °C yielded a M n of 61 700 g mol −1 . The thermostability of the obtained copolymers under air (the temperature for 10% weight loss, T d10% > 340 °C) was significantly improved compared to that of VDF copolymers containing 2-trifluoromethacrylic acid or MAF-tBu. Surface hydrophobicity of these copolymers was superior than that of PVDF homopolymer. For example, poly(VDF-co-MAF-C 6 F 13 ) copolymer of 59,000 g mol −1 with 2 mol % MAF-C 6 F 13 only, displayed a higher static water contact angle (114°) than that of PVDF homopolymer (ca. 94°).

Organometallic‐Mediated Alternating Radical Copolymerization of tert‐Butyl‐2‐Trifluoromethacrylate with Vinyl Acetate and Synthesis of Block Copolymers Thereof

“…The 21% weight loss of the poly(VAc‐ alt ‐MAF‐TBE) copolymer just above 150 °C (versus a reduced weight loss for the block copolymer and no loss for PVAc, Figure S33, Supporting Information) matches the value calculated for the loss of the carbo‐ tert ‐butoxy groups of the MAF‐TBE monomers. It is likely due to the tert ‐butyl ester group decomposition into a carboxylic acid function with release of isobutene, followed by the decarboxylation of the carboxylic acid group (Scheme S1) . The polymers exhibited glass transition temperatures ( T g s) depending on both the monomer compositions and sequences (Figure ).…”

Fluoropolymers: The Right Material for the Right Applications

“… Synthesis of different functional 2‐trifluoromethacrylates (MAF‐esters) from 2‐trifluoromethacrylic acid and their radical copolymerizations for specific materials …”

“…[20,21] Scheme2.Synthesis of different functional 2-trifluoromethacrylates (MAFesters) from 2-trifluoromethacrylic acid andtheir radical copolymerizations for specific materials. [23][24][25][26][27] Figure 2. Original Lumiflon (X = Cl) or Zeffle (X = F) resins/paintsb ased on an alternatedstructure containingC TFE or TFE and functional vinyl ether units.…”

Well-defined copolymers based on poly(vinylidene fluoride): From preparation and phase separation to application

“…33 The controlled behavior of the copolymerization of VDF with tert ‐butyl 2‐trifluoromethacrylate (MAF‐TBE) was clearly demonstrated by monitoring the kinetics. Closely related to this research, the copolymerization of vinylidene fluoride with fluoroalkyl 2‐trifluoromethacrylate (MAF‐C 6 F 13 ) was investigated, resulting in thermostable random copolymers demonstrating improved hydrophobicity with respect to PVDF homopolymers …”