Alternating Sequence Control for Carboxylic Acid and Hydroxy Pendant Groups by Controlled Radical Cyclopolymerization of a Divinyl Monomer Carrying a Cleavable Spacer |
| |
| Authors: | Prof Makoto Ouchi Marina Nakano Tomoya Nakanishi Prof Mitsuo Sawamoto |
| |
| Institution: | 1. Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Kyoto, Japan;2. Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST), Saitama, Japan |
| |
| 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 by 13C 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. |
| |
| Keywords: | cyclopolymerization lower critical solution temperature (LCST) methacrylic acid radical polymerization vinyl |
|
|
