Synthesis and theoretical studies of the conformational behaviour of N-vinylcaprolactam/N-vinylimidazole copolymers in selective solvent†

Bulk radical copolymerisation of N-vinylcaprolactam (VCL) and N-vinylimidazole (VI) is studied experimentally and theoretically. It is shown that the copolymer composition is maintained up to high comonomer conversions. This is explained by a constant ratio of concentrations of comonomers in the reaction zone. The copolymers obtained show thermally induced conformational behaviour. In an aqueous medium above 60 °C, they can form compact globular structures with a hydrophobic core of VCL monomer units covered by a hydrophilic corona of VI monomer units, which allows them to be considered as a basis for thermally switchable functional nanostructures.