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

Abstract

Organometallic-mediated radical polymerization (OMRP) has given access to well-defined poly(vinyl acetate-alt-tert-butyl-2-trifluoromethacrylate)-b-poly(vinyl acetate) and poly(VAc-alt-MAF-TBE) copolymers composed of two electronically distinct monomers: vinyl acetate (VAc, donor, D) and tert-butyl-2-trifluoromethacrylate (MAF-TBE, acceptor, A), with low dispersity (≤1.24) and molar masses up to 57 000 g mol . These copolymers have a precise 1:1 alternating structure over a wide range of comonomer feed compositions. The reactivity ratios are determined as r = 0.01 ± 0.01 and r = 0 at 40 °C. Remarkably, from a feed containing >50% molar VAc content, poly(VAc-alt-MAF-TBE)-b-PVAc block copolymers are produced via a one-pot synthesis. Such diblock copolymers exhibit two glass transition temperatures attributed to the alternating and homopolymer sequences. The OMRP of this fluorine-containing alternating monomer system may provide access to a wide range of new polymer materials.

Fluoroalkyl Pentacarbonylmanganese(I) Complexes as Initiators for the Radical (co)Polymerization of Fluoromonomers

“…It is noted that the temperatures used for these polymerizations are equivalent or lower than that of the corresponding VDF polymerizations (i.e., up to 80 • C with compound 3 in entry 4, vs. 100 • C for the VDF polymerization). The 1 H and 19 F NMR spectra ( Figures S20 and S21, respectively) of the isolated copolymer ( Table 5, entry 4) are in agreement with the previously published ones [42,44] and clearly show the perfect alternation of comonomers since no 1 H NMR signal centered at δ 4.9 ppm (the typical chemical shift of VAc-VAc dyads) was observed.…”

“…Four copolymerizations of vinyl acetate (VAc) and tert-butyl 2-(trifluoromethyl)acrylate (MAF-TBE) were carried out using compounds 3 and 6 as initiators (Scheme II). This copolymer was previously synthesized by conventional [41] OMRP using cobalt(II) acetylacetonate as a controlling agent [42] and RAFT polymerization [43]. All these four co-polymerizations led to copolymers, which display a perfectly alternating structure, in agreement with the measured reactivity ratios that are both close to zero [41].…”

Bis(formylphenolato)cobalt(II)-Mediated Alternating Radical Copolymerization of tert-Butyl 2-Trifluoromethylacrylate with Vinyl Acetate

“…Indeed, the isolated polymers had higher molar masses, according to the SEC analyses (Table S1), than predicted for a controlled polymerization. Attempts to obtain a homopolymer from MAF-TBE in the presence of 3 failed as expected, since this monomer does not homopolymerize under radical conditions [35,36].…”

“…Its performances in the bulk polymerization of VAc and in the bulk copolymerization of VAc and tert -butyl 2-trifluoromethylacrylate (MAF-TBE) are evaluated here. The combination of these two monomers was recently shown to radically polymerize in a strictly alternating fashion (their reactivity ratios are essentially zero) [34] and to be well controlled by Co(acac) 2 [35]. Fluorinated copolymers containing 2-(trifluoromethyl)acrylic acid (MAF) and alkyl 2-trifluoromethacrylates (MAF-esters) may have applications in molecularly imprinted polymers, microlithography, polymer gel electrolyte membranes for fuel cells, and polymer electrolytes for Li-ion batteries [36].…”

Cobalt-Mediated Radical Copolymerization of Chlorotrifluoroethylene and Vinyl Acetate

“…Recently, Ameduri et al reported another case in [35], where an organometallically mediated radical polymerization of VDF with an organocobalt compound R 0 (VAc) n Co III (acac) 2 (R 0 = primary radical generated by V-70, n ≈ 4) as initiator was achieved. Besides these, there were also some studies reporting the cobalt-mediated radical copolymerization of fluorinated monomers and VAc in the last two years [36,37,38]. However, the fluorinated monomers used in these works have no fluorine atom on the double bond, meaning that they have very similar chemical properties with non-fluorinated monomers.…”