Electrografting of Acrylic and Methacrylic Monomers onto Metals: Influence of the Relative Polarity and Donor–Acceptor Properties of the Monomer and the Solvent

Abstract

The possibility of grafting a series of alkyl polyacrylates and polymethacrylates onto a nickel cathode by electropolymerization of the parent monomers has been investigated and has emphasized the critical importance of the solvent used. Indeed, the intensity of the inhibition peak, which is the electrochemical mark of the cathode passivation as result of the polymer grafting, clearly depends on both the polarity and the donor‐acceptor properties of the solvent. The Gutmann concept is used to account for these experimental results. An increase in the donicity of the solvent used for the electrochemical medium has allowed, for the very first time, several polyacrylates and polymethacrylates [such as poly(ethyl acrylate), poly(methyl methacrylate), and poly(2‐trimethylsilyloxyethyl methacrylate)] to be electrografted onto Ni. This observation is consistent with a competition process between the monomer and the solvent for being adsorbed on the cathode and amassing in its very close vicinity. The outcome of this competition is controlled by the relative polarity (in case of low donicity) and the relative donor‐acceptor properties (when the difference is high enough) of the monomer/solvent pair, and by the monomer concentration (in case of weak competition). A semi‐quantitative relationship has also been observed between the monomer ability to be electrografted and the electron‐accepting character of the vinyl β‐carbon atom as measured by 13C NMR.

Synthesis of well‐defined polymeric activated esters

“…87 Besides the electrochemical polymerization of pyrroles and thiophenes, there has been research efforts in electrografting arcylates and methacrylates from electrodes. 88, 89 Jerome et al showed that it is possible to induce reactivity to surfaces of conducting substrates by electrografting NHSA. 90 The resulting strongly adhering coating can act as a versatile reactive film to anchor a variety of amino functionalized molecules, such as catalysts, proteins or amino end-functionalized polymers.…”

Sequential Electrografting and Ring‐Opening Metathesis Polymerization: a Strategy for the Tailoring of Conductive Surfaces

“…As previously reported, [10] the ability for a monomer to be electrografted on a conducting surface strongly depends on the monomer capability to compete with the solvent for adsorption at the cathode surface. It has been shown that solvents with a high donor number (e.g., DMF) are weakly adsorbed on the electrode surface and are thus easily displaced by a large range of (meth)acrylic monomers that can accordingly be electrografted with success.…”

New Monomers Tailored for Direct Electrografting onto Carbon in Water

“…It was shown that an increase in the monomer concentration in an organic solvent usually improved film thickness and coating properties. [6] Unfortunately, this strategy could not be applied to dmaea-C 10 because of a low solubility in water (maximum 0.02 M).…”