title: Alternating Sequence Control for Carboxylic Acid and Hydroxy Pendant Groups by Controlled Radical Cyclopolymerization of a Divinyl Monomer Carrying a Cleavable Spacer.
abstract: By utilizing features of the hemiacetal ester (HAE) bond: easy formation from vinyl ether and carboxylic acid and easy cleavage into different functional groups (-COOH and -OH), we achieved control of the alternating sequence of two functional pendant groups of a vinyl copolymer. Methacrylate- and acrylate-based vinyl groups were connected through HAE bonds to prepare a cleavable divinyl monomer, which was cyclo-polymerized under optimized conditions in a ruthenium-catalyzed living radical polymerization. Subsequent cleavage of the HAE bonds in the resultant cyclo-pendant led to a copolymer consisting of alternating methacrylic acid and 2-hydroxyethyl acrylate units as analyzed by13C NMR spectroscopy. The alternating sequence of -COOH and -OH pendants specifically provided a lower critical solution temperature (LCST) in an ether solvent, which was not observed with the random copolymer of same composition ratio.
authors.affiliation: Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto, 615-8510, Japan.|Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST), 4-1-8 Kawaguchi, Saitama, 332-0012, Japan.
authors.forename: Makoto
authors.identifier: 0000-0003-4540-7827
authors.initials: M
authors.lastname: Ouchi
authors.affiliation: Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto, 615-8510, Japan.
authors.forename: Marina
authors.initials: M
authors.lastname: Nakano
authors.affiliation: Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto, 615-8510, Japan.
authors.forename: Tomoya
authors.initials: T
authors.lastname: Nakanishi
authors.affiliation: Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto, 615-8510, Japan.
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Sawamoto
keywords: cyclopolymerization; lower critical solution temperature (LCST); methacrylic acid; radical polymerization; vinyl