One-pot controlled synthesis of double thermoresponsive N-vinylcaprolactam-based copolymers with tunable LCSTsElectronic supplementary information (ESI) available: Additional structural characterizations and thermal response studies of the copolymers were carried out by nuclear magnetic resonance, dynamic light scattering, turbidimetry and electronic microscopy. See DOI: 10.1039/c3py00134b

• Main Authors: Kermagoret, Anthony, Fustin, Charles-André, Bourguignon, Maxime, Detrembleur, Christophe, Jérôme, Christine, Debuigne, Antoine
• Format: Journal Article
• Language: English
• Published: 19.03.2013
• ISSN: 1759-9954; 1759-9962
• DOI: 10.1039/c3py00134b

N -Vinylcaprolactam ( N VCL) was copolymerized statistically for the first time in a controlled manner with hydrophilic N -vinylamide or hydrophobic vinylester monomers in order to precisely tune up and down the lower critical solution temperature (LCST) of the resulting copolymers. The incorporation of these segments in complex architectures was also considered. Several narrowly distributed N VCL-based copolymers were prepared by cobalt-mediated radical polymerization (CMRP) using the bis-(acetylacetonato)cobalt( ii ) complex as a controlling agent and N -methyl- N -vinylacetamide ( N MVA), N -vinylacetamide ( N VA), vinyl acetate (VAc) or vinyl pivalate (VPi) as comonomers. P N VCL-containing block copolymers having two discrete LCSTs were also synthesized following a one-pot strategy based on the sequential CMRP of N VCL followed by the copolymerization of N MVA with the residual N VCL. Upon gradual heating of aqueous solutions of such double thermoresponsive copolymers, we noticed a transition from free chains to micelles before full dehydration and collapse of the block copolymers. These advances represent a significant step towards the development of a platform based on thermoresponsive P N VCL copolymers with a single phase separation or multistep assembly behaviors. N -Vinylcaprolactam is copolymerized with N -vinylamides or vinyl esters by cobalt-mediated radical polymerization leading to copolymers with multistep assembly behaviors in water.