“Substitutable” Polymer Brushes: Reactive Poly(methacrylate) Brushes with Exchangeable Alkoxyamine Units in the Side Chain

Abstract

A reactive polymer brush containing alkoxyamine units in the side chains, when heated with an alkoxyamine-terminated fluorinated nongrafted polymer, gave a grafted copolymer brush by a radical crossover reaction of alkoxyamine units. The fluorinated grafted copolymer brush could be converted back to the parent polymer brush upon treatment with an excess of low-molecular alkoxyamine. The reversible change in the surface properties of the brush was confirmed by X-ray photoelectron spectroscopy and contact angle measurements.

Versatility of radical coupling in construction of topological polymers

“…Importantly, the radical crossover reaction might be used as a novel synthetic method to new polymers. By selectively incorporating alkoxyamine units into the main chains or side chains of polymers, various topological polymers had been realized, such as gra, [258][259][260] star-shaped, 261-266 crosslinked, 267-270 macrocyclic 271 and block polymers. 254,272,273 Related work was reviewed by Takahara et al, 102 and the detailed progress is not described here any further.…”

Radical crossover reactions of a dynamic covalent polymer brush for reversible hydrophilicity control

“…It was confirmed that the peak of nitrogen was monomodal after the grafting. The results indicated that the dynamic covalent exchange reaction of 3 with P4VP containing an alkoxyamine terminal successfully afforded grafted copolymer brush 4 in the same manner on the outermost of polymer brush as grafting of fluorinated polymers case [33,34].…”

“…However, these approaches are still limited, because the obtained surfaces reciprocate only a few characteristics, owing to limitations of chemical composition. Recently, we presented a novel chemical method for realizing polymer brushes for reversible compositions and hydrophobicity control employing reversible covalent bonds [33,34]. The advantage of these reversible covalent bonds known as "dynamic covalent bonds" [35] is their tolerance for functionalities.…”

Reorganization of polymer structures based on dynamic covalent chemistry: polymer reactions by dynamic covalent exchanges of alkoxyamine units

“…Side-chain-type reactions were further applied in a polymer brush to reversibly alternate its surface properties. 94,95 Reactive poly(methacrylate)-based polymer brushes (15) with radically exchangeable alkoxyamine units in the side chains were prepared on flat silicon substrates, and their reactivities and surface properties were investigated (Scheme 11). The reactive polymer brushes (15) were prepared by surface-initiated ATRP, and the graft density of the brushes was estimated to be B0.36 chains nm À2 .…”