Polyacrylamide pseudo crown ethers via hydrogen bond-assisted cyclopolymerization

Abstract

Polyacrylamide pseudo crown ethers with large in-chain rings (15–24 membered) were synthesized by hydrogen bond-mediated cyclopolymerization of bisacrylamides comprising poly(ethylene oxide) spacers (PEGnDAAm, ethylene oxide units: n = 3–6). The monomers undergo the intramolecular hydrogen bonding of the bisacrylamide units in halogenated solvents to dynamically place the two olefins adjacently. As a result, the bisacrylamides homogeneously allowed controlled radical cyclopolymerization without any macroscopic gelation in 1,2-dichloroethane, even at relatively high concentration of monomers (200 mM), to directly provide precision cyclopolyacrylamides and the related copolymers with high cyclization efficiency (84–98%). Owing to the in-chain ring pendants, a cyclopolyacrylamide had glass transition temperature higher than a corresponding polyacrylamide with linear pendants. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 3294–3302