Poly(fluoroacrylate)s with tunable surface hydrophobicity via radical copolymerization of 2,2,2-trifluoroethyl α-fluoroacrylate and 2-(trifluoromethyl)acrylic acid

International audience; The synthesis of poly(fluoroacrylate)s with tunable wettability and improved adhesion for potential applicationas functional coatings was achieved via radical copolymerization of 2,2,2-trifluoroethylα-fluoroacrylate (FATRIFE) with 2-(trifluoromethyl)acrylic acid (MAF), an adhesion-promoting monomer.These copolymerizations, initiated by tert-butyl peroxypivalate at varying comonomer feed ([FATRIFE]0/[MAF]0) ratios led to a series of poly(FATRIFE-co-MAF) copolymers with different molar compositions infair to good conversions (32–87%) depending on the MAF feed content. The microstructures of the synthesizedpoly(FATRIFE-co-MAF) copolymers were determined by 19F NMR spectroscopy. Even at MAFfeed contents higher than 50%, MAF incorporation into the copolymers was lower than 50%, since MAFdoes not undergo any homopolymerization under radical polymerization conditions. The reactivity ratiosof the (FATRIFE; MAF) monomer pair were also determined (rFATRIFE = 1.65 ± 0.07 and rMAF = 0 at 56 °C)evidencing the formation of statistical copolymers. Initiation involving a highly branched perfluorinatedradical that released a •CF3 radical enabled the demonstration of the regioselective attack of the latterradical onto the CH2 of FATRIFE. The resulting poly(FATRIFE-co-MAF) copolymers exhibited various glasstransition temperatures (Tgs) depending on their compositions. Tg values increased with increasing MAFcontents in the copolymer. In addition, their thermal stability (the temperature for 10% weight loss in air,Td10%) increased with increasing FATRIFE content in the copolymer and reached 348 °C (for that containing93 mol% FATRIFE). Finally, a high copolymer MAF content led to both a good adhesion onto metalsubstrates and to improved hydrophilicity, as revealed by the decrease of the water contact angle from107° (for a reference PFATRIFE homopolymer) to 81° (for a copolymer containing 42 mol% MAF).