Synthesis of cucurbit[6]uril pendent upper critical solution temperature type copolymers: self-assembly and multi-stimuli-responsive behavior

Cucurbit[6]uril-derivatized vinyl monomer (cucurbit[6]uril methacrylate) was synthesized. Acrylic acid (AA) was used as the comonomer for copolymerization with the cucurbit[6]uril-derivatized monomer. A series of copolymers of poly(acrylic acid- co -cucurbit[6]uril methacrylate) (PAA- co -CB[6]MA) were synthesized by free radical polymerization. The cucurbit[6]uril-derivatized monomer and PAA- co -CB[6]MA copolymers were characterized by 1 H NMR spectra, high-resolution mass spectroscopy and gel permeation chromatography. The solution behavior was examined using UV–visible spectroscopy and dynamic light scattering. The PAA- co -CB[6]MA showed an upper critical solution temperature (UCST) in water. The UCST-type thermoresponsive behavior of these CB[6]-derivatized copolymers was highly dependent on the composition of the copolymer. For the same type of copolymer, changes in its composition gave rise to different UCSTs. Additionally, the PAA- co -CB[6]MA copolymers were successful in trapping azocarmine B. The stimuli-responsive release of encapsulated azocarmine B was achieved by a combination of temperature and pH value stimuli. According to the results, the novel PAA- co -CB[6]MA copolymers can be used as carriers. © 2021 Society of Industrial Chemistry.