A kind of polyrotaxane (PR)-based block copolymers was synthesized via the atom transfer radical polymerization (ATRP) of hydroxylethylene acrylate (HEA) initiated by polypseudorotaxanes (PPRs) built from a distal 2-bromoisobutyryl end-capped polypropylene glycol-polyethylene glycol- polypropylene glycol (PPO-PEO-PPO) with a varying amount of -cyclodextrins (-CDs) in the presence of Cu(I)Cl and N

N

N'

N'

N-pentamethyldiethylenetriamine (PMDETA) as catalyst at 20 ℃ in aqueous solution.The supramolecular structure of the resulting copolymers was characterized by means of 1H-NMR

GPC

FTIR

WXRD

DSC and TGA measurements.It was shown that the PHEA segments were attached to two ends of PPRs to give rise to the PR-based block copolymers featured by a characteristic channel-type crystal structure.The entrapped -CD number was increased with the feeding molar ratio

but only about one third added -CDs were retained on the polymer chain after the ATRP process.However

the polymerization degree of PHEA (DP) segments was well controllable with changing the molar feed ratio.In addition

-CDs were observed to favourably aggregate around the PPO segments and nearly cannot accommodate with the PEG segments after incubation in water and freeze-drying.However

according to TGA analyses

there were around one-third of the threaded -CDs enabling to slide to the PEO segments after being treated with DMF and anhydrous ether.The results suggested that these PR-based block copolymers exhibit the solvent-responsibility with the potential to be used as solid smart materials.