Unexpected Alternated Radical Copolymerization of Vinylidene Cyanide with a Fluorinated Vinyl Ether for Superhydrophobic and Highly Oleophobic Films

International audienceThe synthesis and the characterization of original copolymers based on vinylidene cyanide (VCN) and 1H,1H,2H,2H-perfluorodecyl vinyl ether (FAVE8) are presented. While VCN is known to be very reactive in radical homopolymerization in contrast to the vinyl ether which does not homopolymerize, the radical copolymerization of VCN with FAVE8 unexpectedly led to alternating poly(VCN-alt-FAVE8) copolymers. Seven radical copolymerization reactions were investigated with [VCN]0/[FAVE8]0 percent molar ratios ranging between 15/85 and 80/20. The copolymer compositions of these copolymers were assessed by elemental analyses and showed 32 mol % (in one case only) to 56 mol % of VCN (ca. 50 mol % in most cases). From the monomer-polymer copolymerization curve, the Fineman-Ross and Kelen-Tüdos laws enabled one to assess the reactivity ratios (rVCN ) r12 ) 0.08 ( 0.01; rFAVE8 ) r21) 0.07 ( 0.01 at 75 °C) while the revised patterns scheme led to r12 ) 2.7 × 10-3 and r21 ) 4.0 × 10-6, suggesting an alternating tendency of that radical copolymerization. Thermogravimetric analysis of these copolymers showed exceptional thermal stability, the thermal degradation starting from 350 °C under air. Original films processed from these poly(VCN-alt-FAVE8) copolymers exhibit superhydrophobic and highly oleophobic characters as evidenced by high water and diiodomethane contact angles of 168 ± 3 ° and 135 ± 3 °, respectively. These interesting properties make them candidate for some coating applications