Synthesis of Well-Defined Alternating Copolymer Composed of Ethylmaleimide and Hydroxy-Functionalized Vinyl Ether by RAFT Polymerization and Their Thermoresponsive Properties

Jin Motoyanagi; Ayaha Oguri; Masahiko Minoda

doi:10.3390/polym12102255

Synthesis of Well-Defined Alternating Copolymer Composed of Ethylmaleimide and Hydroxy-Functionalized Vinyl Ether by RAFT Polymerization and Their Thermoresponsive Properties

Polymers (Basel). 2020 Oct 1;12(10):2255. doi: 10.3390/polym12102255.

Authors

Jin Motoyanagi¹, Ayaha Oguri¹, Masahiko Minoda¹

Affiliation

¹ Faculty of Molecular Chemistry and Engineering, Graduate School of Science and Technology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan.

Abstract

Here we report the controlled synthesis of alternating copolymers by reversible addition-fragmentation chain transfer (RAFT) polymerization of hydroxy-functionalized vinyl ether (DEGV) and ethylmaleimide (EtMI) using dithiocarbonate derivative (CPDB) as the RAFT reagent. The resulting alternating copolymer poly[ethylmaleimide-alt-(diethylene glycol mono vinyl ether)] (poly(MalMI-alt-DEGV)) had a relatively narrow molecular weight distribution (M_w/M_n < 1.4). These polymers are fully soluble in cold water (5 °C) and an aqueous solution of poly(MalMI-alt-DEGV) became turbid upon heating (using an incident wavelength of 600 nm and 1.0 mg mL^-1 (0.1 wt %) polymer concentration), indicating phase separation above the cloud point temperature (T_cp). The T_cp of the polymer solution ranged from 15-35 °C, depending on the molecular weight and molecular weight distribution of the polymer.

Keywords: RAFT copolymerization; alternating copolymer; hydroxy-functionalized vinyl ether; thermoresponsive property.